BZOJ 一句话题解
菜鸡刷题记录
[题号：题解]
1008：简单排列组合
#include <bits/stdc++.h>
using namespace std; #define ll long long
const ll MOD = (ll)1e5 + ;
ll n, m; ll qmod(ll base, ll n)
{
ll res = ;
while (n)
{
if (n & ) res = res * base % MOD;
base = base * base % MOD;
n >>= ;
}
return res;
} int main()
{
while (scanf("%lld%lld", &m, &n) != EOF)
printf("%lld\n", (qmod(m, n) - (m % MOD * qmod(m - , n - ) % MOD) + MOD) % MOD);
return ;
}
1012：BIT维护后缀最大
#include <bits/stdc++.h>
using namespace std; #define N 1000010
#define ll long long
int m, n; ll D; struct BIT
{
ll a[N];
void Init() { memset(a, , sizeof a); }
void update(int x, ll val)
{
for (; x; x -= x & -x)
a[x] = max(a[x], val);
}
ll query(int x)
{
ll res = ;
for (; x <= n; x += x & -x)
res = max(res, a[x]);
return res;
}
}bit; void Run()
{
scanf("%d%lld", &m, &D);
bit.Init();
char op; ll x, lastans = ; n = ;
for (int i = ; i <= m; ++i)
{
scanf(" %c%lld", &op, &x);
if (op == 'Q') printf("%lld\n", lastans = bit.query(n - x + ));
else bit.update(++n, (x + lastans) % D);
}
} int main()
{
#ifdef LOCAL
freopen("Test.in", "r", stdin);
#endif Run();
return ; }
1051：Tarjan缩点
#include <bits/stdc++.h>
using namespace std; #define pii pair <int, int>
#define N 10010 int n, m;
map <pii, bool> mp;
vector <int> G[N];
int Low[N], DFN[N], Stack[N], Belong[N], sze[N], degree[N], cnt, sec, top;
bool Instack[N]; void Tarjan(int u)
{
Low[u] = DFN[u] = ++cnt;
Stack[top++] = u;
Instack[u] = ;
for (int i = , len = G[u].size(); i < len; ++i)
{
int v = G[u][i];
if (!DFN[v])
{
Tarjan(v);
Low[u] = min(Low[u], Low[v]);
}
else if (Instack[v]) Low[u] = min(Low[u], DFN[v]);
}
if (DFN[u] == Low[u])
{
++sec; int v;
do
{
v = Stack[--top];
Instack[v] = ;
Belong[v] = sec;
++sze[sec];
} while (v != u);
}
} int Run()
{
for (int i = ; i <= n; ++i) if (!DFN[i])
Tarjan(i);
for (int u = ; u <= n; ++u)
{
for (int i = , len = G[u].size(); i < len; ++i)
{
int v = G[u][i];
if (Belong[v] != Belong[u])
++degree[Belong[u]];
}
}
int flag = ;
for (int i = ; i <= sec; ++i) if (!degree[i]) ++flag;
if (flag > ) return ;
for (int i = ; i <= sec; ++i) if (!degree[i])
return sze[i];
return ;
} int main()
{
while (scanf("%d%d", &n, &m) != EOF)
{
for (int i = ; i <= n; ++i) G[i].clear();
mp.clear(); cnt = ; sec = ; top = ;
memset(sze, , sizeof sze);
memset(degree, , sizeof degree);
for (int i = , u, v; i <= m; ++i)
{
scanf("%d%d", &u, &v);
if(mp.find(pii(u, v)) != mp.end()) continue;
G[u].push_back(v);
mp[pii(u, v)] = ;
}
printf("%d\n", Run());
}
return ;
}
1086：树分块
#include <bits/stdc++.h>
using namespace std; #define N 1010 int n, b;
vector <int> G[N];
stack <int> sta;
int Belong[N], sze[N], cap[N], cnt; void DFS(int u, int fa)
{
sze[u] = ;
sta.push(u);
for (int i = , v, len = G[u].size(); i < len; ++i) if ((v = G[u][i]) != fa)
{
DFS(v, u);
sze[u] += sze[v];
if (sze[u] >= b)
{
sze[u] = ;
cap[++cnt] = u;
while (!sta.empty() && sta.top() != u) { Belong[sta.top()] = cnt; sta.pop(); }
}
}
++sze[u];
} void DFS2(int u, int fa, int sp)
{
Belong[u] ? sp = Belong[u] : Belong[u] = sp;
for (int i = , v, len = G[u].size(); i < len; ++i) if ((v = G[u][i]) != fa)
DFS2(v, u, sp);
} void Run()
{
while (scanf("%d%d", &n, &b) != EOF)
{
if (n < b) { puts(""); continue; }
for (int i = ; i <= n; ++i) G[i].clear();
while (!sta.empty()) sta.pop();
cnt = ;
memset(Belong, , sizeof Belong);
for (int i = , u, v; i < n; ++i)
{
scanf("%d%d", &u, &v);
G[u].push_back(v);
G[v].push_back(u);
}
DFS(, ); DFS2(, , cnt);
if (!cnt) cap[cnt = ] = ;
printf("%d\n", cnt);
for (int i = ; i <= n; ++i) printf("%d%c", Belong[i], " \n"[i == n]);
for (int i = ; i <= cnt; ++i) printf("%d%c", cap[i], " \n"[i == cnt]);
}
} int main()
{
#ifdef LOCAL
freopen("Test.in", "r", stdin);
#endif Run();
return ; }
1216：模拟+优先队列，主要不要暴力枚举时间
#include <bits/stdc++.h>
using namespace std; #define N 1501000
#define ll long long
struct node
{
int id, pri; ll arrive, time;
int scan() { return scanf("%d%lld%lld%d", &id, &arrive, &time, &pri); }
void output(ll now) { printf("%d %lld\n", id, now); }
bool operator < (const node &r) const
{
return pri < r.pri || (pri == r.pri && id > r.id);
}
}arr[N]; priority_queue <node> q; int main()
{
int n;
for (n = ; ; ++n) if (arr[n].scan() == EOF) break; --n;
while (!q.empty()) q.pop();
ll t = ;
for (int i = ; i <= n; ++i)
{
if (q.empty())
{
q.push(arr[i]);
t = max(t, arr[i].arrive);
}
else
{
node tmp = q.top();
while (t + tmp.time <= arr[i].arrive)
{
t += tmp.time;
q.pop();
tmp.output(t);
if (q.empty()) break;
tmp = q.top();
}
if (t < arr[i].arrive && !q.empty())
{
ll gap = arr[i].arrive - t;
tmp = q.top(); q.pop();
tmp.time -= gap;
q.push(tmp);
t = arr[i].arrive;
}
q.push(arr[i]);
t = max(t, arr[i].arrive);
}
}
while (!q.empty())
{
node tmp = q.top(); q.pop();
t += tmp.time;
tmp.output(t);
}
return ;
}
1635：差分+坑 有重复
#include <bits/stdc++.h>
using namespace std; #define N 10100
#define pii pair <int, int>
int n, i, h, q;
int ans[N];
map <pii, bool> mp; int main()
{
while (scanf("%d%d%d%d", &n, &i, &h, &q) != EOF)
{
memset(ans, , sizeof ans);
mp.clear();
for (int i = , l, r; i <= q; ++i)
{
scanf("%d%d", &l, &r);
if (l > r) swap(l, r);
if (mp.find(pii(l, r)) != mp.end()) continue;
mp[pii(l, r)] = ;
--ans[l + ]; ++ans[r];
}
for (int i = ; i <= n; ++i) ans[i] += ans[i - ];
for (int i = ; i <= n; ++i) printf("%d\n", h + ans[i]);
}
return ;
}
1935：排序一维，树状数组一维
#include <bits/stdc++.h>
using namespace std; #define N 3000010 int n, q, m;
int ans[N], brr[N];
struct node
{
// 0 insert
// 1 add
// 2 sub
int op, x, y, id;
node() {}
node(int op, int x, int y, int id) : op(op), x(x), y(y), id(id) {}
bool operator < (const node &r) const
{
return x == r.x ? id < r.id : x < r.x;
}
}arr[N]; struct BIT
{
int a[N]; void Init()
{
memset(a, , sizeof a);
} void update(int x, int val)
{
while (x <= m)
{
a[x] += val;
x += x & -x;
}
} int query(int x)
{
int res = ;
while (x)
{
res += a[x];
x -= x & -x;
}
return res;
}
}bit; void Hash()
{
sort(brr + , brr + + m);
int tmp = unique(brr + , brr + + m) - brr - ;
for (int i = ; i <= m; ++i)
arr[i].y = lower_bound(brr + , brr + + tmp, arr[i].y) - brr;
} void Run()
{
while (scanf("%d%d", &n, &q) != EOF)
{
m = n;
for (int i = , x, y; i <= n; ++i)
{
scanf("%d%d", &x, &y);
arr[i] = node(, x, y, );
brr[i] = y;
}
for (int i = , x[], y[]; i <= q; ++i)
{
for (int j = ; j < ; ++j) scanf("%d%d", x + j, y + j);
arr[++m] = node(, x[], y[], i); brr[m] = y[];
arr[++m] = node(, x[] - , y[] - , i); brr[m] = y[] - ;
arr[++m] = node(-, x[], y[] - , i); brr[m] = y[] - ;
arr[++m] = node(-, x[] - , y[], i); brr[m] = y[];
}
Hash();
sort(arr + , arr + + m);
for (int i = ; i <= m; ++i)
{
if (arr[i].id == ) bit.update(arr[i].y, );
else
ans[arr[i].id] += bit.query(arr[i].y) * arr[i].op;
}
for (int i = ; i <= q; ++i) printf("%d\n", ans[i]);
}
} int main()
{
#ifdef LOCAL
freopen("Test.in", "r", stdin);
#endif Run();
return ;
}
2014：虚树+DP
#include <bits/stdc++.h>
using namespace std; #define ll long long
#define INF 0x3f3f3f3f3f3f3f3f
#define N 1000010
int n, q, k, a[N]; struct Graph
{
struct node
{
int to, nx;
node() {}
node(int to, int nx) : to(to), nx(nx) {}
}a[N << ];
int head[N], pos;
void init() { memset(head, , sizeof head); pos = ; }
void add(int u, int v)
{
a[++pos] = node(v, head[u]); head[u] = pos;
a[++pos] = node(u, head[v]); head[v] = pos;
}
}g[];
#define erp(id, u) for (int it = g[id].head[u], v = g[id].a[it].to; it; it = g[id].a[it].nx, v = g[id].a[it].to) int fa[N], son[N], top[N], p[N], cnt; ll deep[N], sze[N];
void DFS(int u)
{
sze[u] = ;
erp(, u) if (v != fa[u])
{
fa[v] = u;
deep[v] = deep[u] + ;
DFS(v); sze[u] += sze[v];
if (!son[u] || sze[v] > sze[son[u]]) son[u] = v;
}
} void getpos(int u, int sp)
{
top[u] = sp;
p[u] = ++cnt;
if (!son[u]) return;
getpos(son[u], sp);
erp(, u) if (v != fa[u] && v != son[u])
getpos(v, v);
} int querylca(int u, int v)
{
while (top[u] != top[v])
{
if (deep[top[u]] < deep[top[v]]) swap(u, v);
u = fa[top[u]];
}
if (deep[u] > deep[v]) swap(u, v);
return u;
} ll Max[N], Min[N], sum[N], res_Max, res_Min, res_sum; int vis[N];
void dp(int u, int fa)
{
Max[u] = ; Min[u] = INF; sum[u] = ;
sze[u] = vis[u];
erp(, u) if (v != fa)
dp(v, u), sze[u] += sze[v];
if (vis[u]) Max[u] = Min[u] = sum[u] = deep[u];
erp(, u) if (v != fa)
{
sum[u] += sum[v];
res_sum += (sum[v] - deep[u] * sze[v]) * (sze[u] - sze[v]);
if (Max[u]) res_Max = max(res_Max, Max[u] + Max[v] - * deep[u]);
Max[u] = max(Max[u], Max[v]);
if (Min[v] != INF) res_Min = min(res_Min, Min[u] + Min[v] - * deep[u]);
Min[u] = min(Min[u], Min[v]);
}
vis[u] = ; g[].head[u] = ;
} bool cmp(int a, int b) { return p[a] < p[b]; } void init()
{
g[].init(); g[].init(); cnt = ;
memset(son, , sizeof son);
} int stktop, stk[N];
void Run()
{
while (scanf("%d", &n) != EOF)
{
init();
for (int i = , u, v; i < n; ++i)
{
scanf("%d%d", &u, &v);
g[].add(u, v);
} deep[] = ; DFS(); getpos(, );
scanf("%d", &q);
for (int qq = ; qq <= q; ++qq)
{
scanf("%d", &k);
for (int i = ; i <= k; ++i) scanf("%d", a + i);
sort(a + , a + + k, cmp);
for (int i = ; i <= k; ++i) vis[a[i]] = ;
stk[stktop = ] = ; g[].pos = ;
for (int i = ; i <= k; ++i)
{
int lca = querylca(stk[stktop], a[i]);
while (deep[lca] < deep[stk[stktop]])
{
if (deep[stk[stktop - ]] <= deep[lca])
{
int last = stk[stktop--];
if (stk[stktop] != lca) stk[++stktop] = lca;
g[].add(last, lca);
break;
}
g[].add(stk[stktop - ], stk[stktop]), --stktop;
}
if (stk[stktop] != a[i]) stk[++stktop] = a[i];
}
while (stktop > ) g[].add(stk[stktop - ], stk[stktop]), --stktop;
res_Max = , res_Min = INF; res_sum = ;
dp(, );
printf("%lld %lld %lld\n", res_sum, res_Min, res_Max);
}
}
} int main()
{
#ifdef LOCAL
freopen("Test.in", "r", stdin);
#endif Run();
return ;
}
2056：特判+不要用iostream
#include <cstdio>
#define ull unsigned long long
int t, a[];
ull res; int main()
{
scanf("%d", &t);
while (t--)
{
for (int i = ; i <= ; ++i) scanf("%d", a + i);
scanf("%llu", &res);
for (int i = ; i <= ; ++i) res += 1ll << a[i];
if (res == ) res = -;
if (res != -) printf("%llu\n", res);
else
{
printf("%llu", res / );
puts("");
}
}
return ;
}
2120：带修改莫队
#include <bits/stdc++.h>
using namespace std; #define N 100010
#define block 400 int n, q, cnt_que, cnt_op;
int arr[N], brr[N], ans[N], cnt[N * ], res; struct QUE
{
int l, r, id, ti;
void scan(int id, int ti)
{
this->id = id;
this->ti = ti;
scanf("%d%d", &l, &r);
}
bool operator < (const QUE &r) const
{
int posl = l / block, posr = r.l / block;
return posl == posr ? this->r < r.r : posl < posr;
}
}que[N]; struct OP
{
int pre, v, id;
void scan()
{
scanf("%d%d", &id, &v);
pre = brr[id];
brr[id] = v;
}
}op[N]; void update(int x, int val)
{
if (val == -)
{
if (cnt[arr[x]] == ) --res;
--cnt[arr[x]];
}
else
{
++cnt[arr[x]];
if (cnt[arr[x]] == ) ++res;
}
} void change(int ti, int vis, int l, int r)
{
int pos = op[ti].id;
int v = vis ? op[ti].v : op[ti].pre;
if (pos >= l && pos <= r)
{
update(pos, -);
arr[pos] = v;
update(pos, );
}
else arr[pos] = v;
} void Run()
{
while (scanf("%d%d", &n, &q) != EOF)
{
cnt_que = cnt_op = res = ;
for (int i = ; i <= n; ++i) scanf("%d", arr + i);
for (int i = ; i <= n; ++i) brr[i] = arr[i];
char opp;
for (int i = ; i <= q; ++i)
{
scanf(" %c", &opp);
if (opp == 'Q') que[++cnt_que].scan(cnt_que, cnt_op);
else op[++cnt_op].scan();
}
sort(que + , que + + cnt_que);
for (int i = , l = , r = , ti = ; i <= cnt_que; ++i)
{
for (; ti < que[i].ti; ++ti) change(ti + , , l, r);
for (; ti > que[i].ti; --ti) change(ti, , l, r);
for (; r < que[i].r; ++r) update(r + , );
for (; r > que[i].r; --r) update(r, -);
for (; l < que[i].l; ++l) update(l, -);
for (; l > que[i].l; --l) update(l - , );
ans[que[i].id] = res;
}
for (int i = ; i <= cnt_que; ++i) printf("%d\n", ans[i]);
}
} int main()
{
#ifdef LOCAL
freopen("Test.in", "r", stdin);
#endif Run();
return ;
}
2141：分块+树状数组
#include <bits/stdc++.h>
using namespace std; #define N 20010
#define block 200 int n, m, q;
int arr[N], brr[N], pos[N], num[N]; struct BIT
{
int a[N];
void update(int x, int val)
{
while (x <= n)
{
a[x] += val;
x += x & -x;
}
} int query(int x)
{
int res = ;
while (x)
{
res += a[x];
x -= x & -x;
}
return res;
} }bit[block]; int query(int x)
{
int res = ;
for (int i = ; i < pos[x]; ++i)
res += num[i] - bit[i].query(arr[x]);
for (int i = x - ; i >= && pos[i] == pos[x]; --i) if (arr[i] > arr[x])
++res;
for (int i = x + ; i <= n && pos[i] == pos[x]; ++i) if (arr[i] < arr[x])
++res;
for (int i = pos[x] + ; i <= pos[n]; ++i)
res += bit[i].query(arr[x] - );
return res;
} void Run()
{
while (scanf("%d", &n) != EOF)
{
for (int i = ; i <= n; ++i) scanf("%d", arr + i);
for (int i = ; i <= n; ++i) brr[i] = arr[i];
sort(brr + , brr + + n);
m = unique(brr + , brr + + n) - brr - ;
for (int i = ; i <= n; ++i) arr[i] = lower_bound(brr + , brr + + m, arr[i]) - brr;
for (int i = ; i <= n; ++i) pos[i] = (i - ) / block + , ++num[pos[i]];
int res = ;
for (int i = ; i <= n; ++i)
{
bit[].update(arr[i], );
res += i - bit[].query(arr[i]);
}
printf("%d\n", res);
for (int i = ; i <= n; ++i) bit[pos[i]].update(arr[i], );
scanf("%d", &q);
for (int i = , l, r; i <= q; ++i)
{
scanf("%d%d", &l, &r);
if (l > r) swap(l, r);
res -= query(l);
res -= query(r);
if (arr[l] > arr[r]) ++res;
bit[pos[l]].update(arr[l], -);
bit[pos[r]].update(arr[r], -);
swap(arr[l], arr[r]);
bit[pos[l]].update(arr[l], );
bit[pos[r]].update(arr[r], );
res += query(l);
res += query(r);
if (arr[l] > arr[r]) --res;
printf("%d\n", res);
}
}
} int main()
{
#ifdef LOCAL
freopen("Test.in", "r", stdin);
#endif Run();
return ;
}
2157：树剖+线段树
#include <bits/stdc++.h>
using namespace std; #define N 100010
#define INF 0x3f3f3f3f
int n, q;
struct Edge { int u, v, w; Edge() {} Edge(int u, int v, int w) : u(u), v(v), w(w) {}}edge[N];
vector <int> G[N];
int p[N], fp[N], sze[N], son[N], fa[N], deep[N], top[N], cnt; void DFS(int u)
{
sze[u] = ;
for (int i = , len = G[u].size(); i < len; ++i)
{
int v = G[u][i];
if (v == fa[u]) continue;
fa[v] = u;
deep[v] = deep[u] + ;
DFS(v); sze[u] += sze[v];
if (!son[u] || sze[v] > sze[son[u]]) son[u] = v;
}
} void getpos(int u, int sp)
{
top[u] = sp;
p[u] = ++cnt;
fp[cnt] = u;
if (!son[u]) return;
getpos(son[u], sp);
for (int i = , len = G[u].size(); i < len; ++i)
{
int v = G[u][i];
if (v == fa[u] || v == son[u]) continue;
getpos(v, v);
}
} struct SEG
{
struct node
{
int sum, Max, Min, lazy;
void init()
{
sum = ;
Max = -INF;
Min = INF;
lazy = ;
}
node operator + (const node &r) const
{
node res; res.init();
res.sum = sum + r.sum;
res.Max = max(Max, r.Max);
res.Min = min(Min, r.Min);
return res;
}
void change()
{
sum *= -;
Max *= -;
Min *= -;
lazy *= -;
swap(Max, Min);
}
}a[N << ], res;
void build(int id, int l, int r)
{
a[id].init();
if (l == r) return;
int mid = (l + r) >> ;
build(id << , l, mid);
build(id << | , mid + , r);
}
void pushdown(int id)
{
if (a[id].lazy != )
{
a[id].lazy = ;
a[id << ].change();
a[id << | ].change();
}
}
void update(int id, int l, int r, int pos, int val)
{
if (l == r)
{
a[id].sum = a[id].Max = a[id].Min = val;
return;
}
pushdown(id);
int mid = (l + r) >> ;
if (pos <= mid) update(id << , l, mid, pos, val);
else update(id << | , mid + , r, pos, val);
a[id] = a[id << ] + a[id << | ];
}
void update(int id, int l, int r, int ql, int qr, int val)
{
if (l >= ql && r <= qr)
{
a[id].change();
return;
}
pushdown(id);
int mid = (l + r) >> ;
if (ql <= mid) update(id << , l, mid, ql, qr, val);
if (qr > mid) update(id << | , mid + , r, ql, qr, val);
a[id] = a[id << ] + a[id << | ];
}
void query(int id, int l, int r, int ql, int qr)
{
if (l >= ql && r <= qr)
{
res = res + a[id];
return;
}
pushdown(id);
int mid = (l + r) >> ;
if (ql <= mid) query(id << , l, mid, ql, qr);
if (qr > mid) query(id << | , mid + , r, ql, qr);
a[id] = a[id << ] + a[id << | ];
}
}seg; void update(int u, int v)
{
while (top[u] != top[v])
{
if (deep[top[u]] < deep[top[v]])
swap(u, v);
seg.update(, , n, p[top[u]], p[u], -);
u = fa[top[u]];
}
if (u == v) return;
if (deep[u] > deep[v]) swap(u, v);
seg.update(, , n, p[son[u]], p[v], -);
} void query(int u, int v)
{
while (top[u] != top[v])
{
if (deep[top[u]] < deep[top[v]])
swap(u, v);
seg.query(, , n, p[top[u]], p[u]);
u = fa[top[u]];
}
if (u == v) return;
if (deep[u] > deep[v]) swap(u, v);
seg.query(, , n, p[son[u]], p[v]);
} int main()
{
while (scanf("%d", &n) != EOF)
{
cnt = ;
for (int i = , u, v, w; i < n; ++i)
{
scanf("%d%d%d", &u, &v, &w); ++u, ++v;
edge[i] = Edge(u, v, w);
G[u].push_back(v);
G[v].push_back(u);
}
DFS();
getpos(, );
seg.build(, , n);
for (int i = ; i < n; ++i)
{
if (edge[i].u != fa[edge[i].v]) swap(edge[i].u, edge[i].v);
seg.update(, , n, p[edge[i].v], edge[i].w);
}
char op[]; int u, v;
scanf("%d", &q);
for (int i = ; i <= q; ++i)
{
scanf("%s%d%d", op, &u, &v); ++u, ++v;
if (op[] == 'N') update(u, v);
else if (op[] == 'C') seg.update(, , n, p[edge[u - ].v], v - );
else
{
seg.res.init();
query(u, v);
if (op[] == 'S') printf("%d\n", seg.res.sum);
else if (op[] == 'I') printf("%d\n", seg.res.Min);
else printf("%d\n", seg.res.Max);
}
}
}
return ;
}
2286：虚数+树形DP
#include <bits/stdc++.h>
using namespace std; #define INFLL 0x3f3f3f3f3f3f3f3f
#define ll long long
#define N 250010
int n, q; struct Edge
{
struct node
{
int to, nx, w;
node() {}
node(int to, int nx, int w) : to(to), nx(nx), w(w) {}
}a[N << ];
int head[N], pos;
void add(int u, int v, int w)
{
a[++pos] = node(v, head[u], w); head[u] = pos;
a[++pos] = node(u, head[v], w); head[v] = pos;
}
}g[];
#define erp(id, u) for (int it = g[id].head[u], v = g[id].a[it].to; it; it = g[id].a[it].nx, v = g[id].a[it].to) int p[N], cnt, deep[N], fa[N], sze[N], son[N], top[N], vis[N]; ll val[N];
void DFS(int u)
{
sze[u] = ;
erp(, u) if (v != fa[u])
{
fa[v] = u;
deep[v] = deep[u] + ;
val[v] = min(val[u], (ll)g[].a[it].w);
DFS(v); sze[u] += sze[v];
if (!son[u] || sze[v] > sze[son[u]]) son[u] = v;
}
} void getpos(int u, int sp)
{
top[u] = sp;
p[u] = ++cnt;
if (!son[u]) return;
getpos(son[u], sp);
erp(, u) if (v != fa[u] && v != son[u])
getpos(v, v);
} int querylca(int u, int v)
{
while (top[u] != top[v])
{
if (deep[top[u]] < deep[top[v]]) swap(u, v);
u = fa[top[u]];
}
if (deep[u] > deep[v]) swap(u, v);
return u;
} ll dp(int u, int fa)
{
ll tmp = ;
erp(, u) if (v != fa) tmp += dp(v, u);
g[].head[u] = ;
if (tmp == || vis[u]) return vis[u] = , val[u];
return min(val[u], tmp);
} bool cmp(int a, int b) { return p[a] < p[b]; } int a[N], stk[N], stktop;
void Run()
{
while (scanf("%d", &n) != EOF)
{
val[] = INFLL;
for (int i = , u, v, w; i < n; ++i)
{
scanf("%d%d%d", &u, &v, &w);
g[].add(u, v, w);
}DFS(); getpos(, );
scanf("%d", &q);
for (int qq = , k; qq <= q; ++qq)
{
scanf("%d", &k);
for (int i = ; i <= k; ++i) scanf("%d", a + i), vis[a[i]] = ;
sort(a + , a + + k, cmp);
stk[stktop = ] = ; g[].pos = ;
for (int i = ; i <= k; ++i)
{
int lca = querylca(a[i], stk[stktop]);
while (deep[lca] < deep[stk[stktop]])
{
if (deep[stk[stktop - ]] <= deep[lca])
{
int last = stk[stktop--];
if (stk[stktop] != lca) stk[++stktop] = lca;
g[].add(last, lca, );
break;
}
g[].add(stk[stktop], stk[stktop - ], ), --stktop;
}
if (stk[stktop] != a[i]) stk[++stktop] = a[i];
}
while (stktop > ) g[].add(stk[stktop], stk[stktop - ], ), --stktop;
printf("%lld\n", dp(, ));
}
}
} int main()
{
#ifdef LOCAL
freopen("Test.in", "r", stdin);
#endif Run();
return ;
}
2654：二分+Kruskal()
#include <bits/stdc++.h>
using namespace std; #define N 100010
struct node
{
int u, v, clo, base, w;
void scan()
{
scanf("%d%d%d%d", &u, &v, &base, &clo);
++u, ++v;
if (clo == ) w = base;
}
bool operator < (const node &r) const
{
return w < r.w || (w == r.w && clo < r.clo);
}
}edge[N];
int n, m, need;
int pre[N];
int find(int x) { return pre[x] == ? x : pre[x] = find(pre[x]); } #define pii pair <int, int>
pii Kruskal(int add)
{
memset(pre, , sizeof pre);
for (int i = ; i <= m; ++i) if (edge[i].clo == ) edge[i].w = add + edge[i].base;
sort(edge + , edge + + m);
int cnt = , cnt_white = ;
int res = ;
for (int i = ; i <= m; ++i)
{
int u = edge[i].u, v = edge[i].v;
int fu = find(u), fv = find(v);
if (fu == fv) continue;
++cnt; if (edge[i].clo == ) ++cnt_white;
res += edge[i].w;
pre[fu] = fv;
if (cnt == n) break;
}
return pii(res, cnt_white);
} int main()
{
while (scanf("%d%d%d", &n, &m, &need) != EOF)
{
for (int i = ; i <= m; ++i) edge[i].scan();
int l = -, r = , res = ;
while (r - l >= )
{
int mid = (l + r) >> ;
pii tmp = Kruskal(mid);
if (tmp.second >= need) res = tmp.first - mid * need, l = mid + ;
else r = mid - ;
}
printf("%d\n", res);
}
return ;
}
2724：$F[i][j] 表示 第i块到第j块的众数是什么，cntblock[i][j]表示前i块中j这个数出现几次，然后分块维护即可$
#include <bits/stdc++.h>
using namespace std; #define N 100010
#define block 650
#define pii pair <int, int>
int n, m, q;
int arr[N], brr[N], cnt[N];
int cntblock[block][N], sze;
pii f[block][block]; void Hash()
{
for (int i = ; i <= n; ++i) brr[i] = arr[i];
sort(brr + , brr + + n);
m = unique(brr + , brr + + n) - brr - ;
for (int i = ; i <= n; ++i) arr[i] = lower_bound(brr + , brr + + m, arr[i]) - brr;
} void Init()
{
memset(cntblock, , sizeof cntblock);
memset(f, , sizeof f);
memset(cnt, , sizeof cnt);
} void clean(int l, int r)
{
for (int i = l; i <= r; ++i)
cnt[arr[i]] = ;
} void Run()
{
while (scanf("%d%d", &n, &q) != EOF)
{
Init(); sze = (n - ) / block + ;
for (int i = ; i <= n; ++i) scanf("%d", arr + i); Hash();
for (int i = ; i <= n; ++i)
{
int now = (i - ) / block + ;
if (i != && (i - ) / block + != now)
for (int j = ; j <= m; ++j)
cntblock[now][j] = cntblock[now - ][j];
++cntblock[now][arr[i]];
}
for (int i = ; i <= sze; ++i)
{
for (int j = i; j <= sze; ++j)
{
f[i][j] = f[i][j - ];
int l = (j - ) * block + , r = j * block;
for (int k = l; k <= r; ++k)
{
int num = arr[k];
if (!cnt[num])
cnt[num] += cntblock[j - ][num] - cntblock[i - ][num];
++cnt[num];
if (cnt[num] > f[i][j].first || cnt[num] == f[i][j].first && brr[num] < f[i][j].second)
f[i][j] = pii(cnt[num], brr[num]);
}
clean(l, r);
}
}
int ans = ;
for (int i = , l, r; i <= q; ++i)
{
scanf("%d%d", &l, &r);
l = (l + ans - ) % n + ;
r = (r + ans - ) % n + ;
if (l > r) swap(l, r);
int posl = (l - ) / block + , posr = (r - ) / block + ;
pii res = pii(, );
if (posl == posr)
{
for (int j = l; j <= r; ++j)
{
int num = arr[j];
++cnt[num];
if (cnt[num] > res.first || cnt[num] == res.first && brr[num] < res.second)
res = pii(cnt[num], brr[num]);
}
clean(l, r);
}
else
{
res = f[posl + ][posr - ];
for (int j = l; j <= posl * block; ++j)
{
int num = arr[j];
if (!cnt[num]) cnt[num] += cntblock[posr - ][num] - cntblock[posl][num];
++cnt[num];
if (cnt[num] > res.first || cnt[num] == res.first && brr[num] < res.second)
res = pii(cnt[num], brr[num]);
}
for (int j = (posr - ) * block + ; j <= r; ++j)
{
int num = arr[j];
if (!cnt[num]) cnt[num] += cntblock[posr - ][num] - cntblock[posl][num];
++cnt[num];
if (cnt[num] > res.first || cnt[num] == res.first && brr[num] < res.second)
res = pii(cnt[num], brr[num]);
}
clean(l, posl * block);
clean((posr - ) * block + , r);
}
printf("%d\n", res.second);
ans = res.second;
}
}
} int main()
{
#ifdef LOCAL
freopen("Test.in", "r", stdin);
#endif Run();
return ;
}
2729：先排男生和老师，老师相邻和不相邻，相邻的话需要插入一个女生
import java.io.BufferedInputStream;
import java.util.Scanner;
import java.math.*; public class Main { static BigInteger fac[] = new BigInteger[4100];
public static void init()
{
fac[0] = BigInteger.ONE;
for (int i = 1; i < 4100; ++i)
fac[i] = fac[i - 1].multiply(BigInteger.valueOf(i));
} public static BigInteger C(int n, int m)
{
if (n < m || n < 0 || m < 0) return BigInteger.ZERO;
return fac[n].divide(fac[m]).divide(fac[n - m]);
} public static void main(String[] args)
{
init();
Scanner in = new Scanner(new BufferedInputStream(System.in));
int n, m;
while (in.hasNext())
{
n = in.nextInt();
m = in.nextInt();
BigInteger a, b;
a = BigInteger.valueOf(2).multiply(fac[n + 1]).multiply(fac[m]).multiply(C(n + 2, m - 1));
b = BigInteger.valueOf(2).multiply(fac[n]).multiply(fac[m]).multiply(C(n + 1, 2)).multiply(C(n + 3, m));
System.out.println(a.add(b));
}
in.close();
}
}
2738：整体二分
#include <bits/stdc++.h>
using namespace std; #define N 510
#define M 60010
#define INF 0x3f3f3f3f
int n, q, m;
struct node
{
int x, y, v;
void scan(int x, int y)
{
this->x = x; this->y = y;
scanf("%d", &v);
}
bool operator < (const node &r) const { return v < r.v; }
}arr[N * N]; struct BIT
{
int a[N][N];
void Init() { memset(a, , sizeof a); }
void update(int x, int y, int val)
{
for (int i = x; i <= n; i += i & -i)
for (int j = y; j <= n; j += j & -j)
a[i][j] += val;
}
int query(int x, int y)
{
int res = ;
for (int i = x; i; i -= i & -i)
for (int j = y; j; j -= j & -j)
res += a[i][j];
return res;
}
int query(int x[], int y[])
{
int res = ;
res += query(x[] - , y[] - );
res += query(x[], y[]);
res -= query(x[] - , y[]);
res -= query(x[], y[] - );
return res;
}
}bit; struct qnode
{
int x[], y[], k, id;
void scan(int id)
{
this->id = id;
for (int i = ; i < ; ++i)
scanf("%d%d", x + i, y + i);
scanf("%d", &k);
}
}que[M], ql[M], qr[M]; int ans[M]; void CDQ(int L, int R, int l, int r)
{
if (L > R) return;
if (l == r)
{
for (int i = L; i <= R; ++i)
ans[que[i].id] = arr[l].v;
return;
}
int mid = (l + r) >> ;
for (int i = l; i <= mid; ++i) bit.update(arr[i].x, arr[i].y, );
int posl = , posr = ;
for (int i = L; i <= R; ++i)
{
int sze = bit.query(que[i].x, que[i].y);
if (sze < que[i].k)
{
que[i].k -= sze;
qr[++posr] = que[i];
}
else
ql[++posl] = que[i];
}
for (int i = ; i <= posl; ++i) que[L + i - ] = ql[i];
for (int i = ; i <= posr; ++i) que[L + posl + i - ] = qr[i];
for (int i = l; i <= mid; ++i) bit.update(arr[i].x, arr[i].y, -);
CDQ(L, L + posl - , l, mid);
CDQ(L + posl, R, mid + , r);
} int main()
{
while (scanf("%d%d", &n, &q) != EOF)
{
m = ; bit.Init();
for (int i = ; i <= n; ++i) for (int j = ; j <= n; ++j) arr[++m].scan(i, j);
sort(arr + , arr + + m);
for (int i = ; i <= q; ++i) que[i].scan(i);
CDQ(, q, , m);
for (int i = ; i <= q; ++i) printf("%d\n", ans[i]);
}
return ;
}
2750：$f[u] 表示st -> u的路径数，g[v] 表示 v所能到达的点数 那么一条边<u, v> 提供的贡献就是 f[u] \cdot g[v]$
#include <bits/stdc++.h>
using namespace std; #define ll long long
#define N 5010
#define INF 0x3f3f3f3f
const ll MOD = (ll)1e9 + ;
int n, m; ll ans[N]; struct Graph
{
struct node
{
int to, nx, w, id;
node() {}
node(int to, int nx, int w, int id) : to(to), nx(nx), w(w), id(id) {}
}a[N << ]; int head[N], pos;
void init()
{
memset(head, -, sizeof head);
pos = ;
}
void add(int u, int v, int w, int id)
{
a[++pos] = node(v, head[u], w, id); head[u] = pos;
}
}G[];
#define erp(G, u) for (int it = G.head[u], v = G.a[it].to, w = G.a[it].w, id = G.a[it].id; ~it; it = G.a[it].nx, v = G.a[it].to, w = G.a[it].w, id = G.a[it].id) namespace Dijkstra
{
struct node
{
int to, w;
node() {}
node(int to, int w) : to(to), w(w) {}
bool operator < (const node &r) const { return w > r.w; }
};
int dist[N]; bool used[N];
void work(int st)
{
for (int i = ; i <= n; ++i) dist[i] = INF, used[i] = false;
priority_queue <node> q; q.push(node(st, )); dist[st] = ;
while (!q.empty())
{
int u = q.top().to; q.pop();
erp(G[], u) if (!used[v] && dist[v] > dist[u] + w)
{
dist[v] = dist[u] + w;
q.push(node(v, w));
}
}
}
} int f[N], g[N], in[N];
void Topo(int p, int *x)
{
G[].init();
for (int i = ; i <= n; ++i) x[i] = p, in[i] = ;
for (int u = ; u <= n; ++u) if (Dijkstra::dist[u] != INF)
{
erp(G[], u) if (Dijkstra::dist[u] + w <= Dijkstra::dist[v])
{
if (!p)
{
G[].add(u, v, w, id);
++in[v];
}
else
{
G[].add(v, u, w, id);
++in[u];
}
}
} queue <int> q;
for (int u = ; u <= n; ++u) if (Dijkstra::dist[u] != INF && !in[u])
{
x[u] = ;
q.push(u);
} while (!q.empty())
{
int u = q.front(); q.pop();
erp(G[], u)
{
x[v] += x[u];
--in[v];
if (!in[v]) q.push(v);
}
}
} void Run()
{
while (scanf("%d%d", &n, &m) != EOF)
{
G[].init();
memset(ans, , sizeof ans);
for (int i = , u, v, w; i <= m; ++i)
{
scanf("%d%d%d", &u, &v, &w);
G[].add(u, v, w, i);
}
for (int i = ; i <= n; ++i)
{
Dijkstra::work(i);
Topo(, g);
Topo(, f);
for (int u = ; u <= n; ++u) erp(G[], u)
ans[id] = (ans[id] + 1ll * f[u] * g[v]) % MOD;
}
for (int i = ; i <= m; ++i) printf("%lld\n", ans[i]);
}
} int main()
{
#ifdef LOCAL
freopen("Test.in", "r", stdin);
#endif Run();
return ;
}
2752：线段树维护，注意区间的合并
#include <bits/stdc++.h>
using namespace std; #define N 100010
#define ll long long
int n, q; ll calc(ll x) { return x * (x + ) / ; }
ll base[N];
struct SEG
{
struct node
{
ll sum, res, lsum, rsum, lazy, cnt, sze;
node() {}
node(ll sum, ll res, ll lsum, ll rsum, ll lazy, ll cnt, ll sze) : sum(sum), res(res), lsum(lsum), rsum(rsum), lazy(lazy), cnt(cnt), sze(sze) {}
node operator + (const node &r) const
{
node ans = node(, , , , , , );
ans.sum = sum + r.sum;
ans.res = res + r.res + rsum * r.cnt + r.lsum * cnt;
ans.lsum = lsum + r.lsum + sum * r.cnt;
ans.rsum = rsum + r.rsum + r.sum * cnt;
ans.cnt = cnt + r.cnt;
ans.sze = sze + r.sze + cnt * r.cnt;
return ans;
}
}a[N << ], res;
void change(int id, ll val)
{
a[id].sum += a[id].cnt * val;
a[id].res += base[a[id].cnt] * val;
a[id].lsum += calc(a[id].cnt) * val;
a[id].rsum += calc(a[id].cnt) * val;
a[id].lazy += val;
}
void pushdown(int id)
{
if (!a[id].lazy) return;
change(id << , a[id].lazy);
change(id << | , a[id].lazy);
a[id].lazy = ;
}
void build(int id, int l, int r)
{
if (l == r)
{
a[id] = node(, , , , , , );
return;
}
int mid = (l + r) >> ;
build(id << , l, mid);
build(id << | , mid + , r);
a[id] = a[id << ] + a[id << | ];
}
void update(int id, int l, int r, int ql, int qr, ll val)
{
if (l >= ql && r <= qr)
{
change(id, val);
return;
}
pushdown(id);
int mid = (l + r) >> ;
if (ql <= mid) update(id << , l, mid, ql, qr, val);
if (qr > mid) update(id << | , mid + , r, ql, qr, val);
a[id] = a[id << ] + a[id << | ];
return;
}
node query(int id, int l, int r, int ql, int qr)
{
if (l >= ql && r <= qr) return a[id];
pushdown(id);
int mid = (l + r) >> ;
node res = node(, , , , , , );
if (ql <= mid) res = query(id << , l, mid, ql, qr);
if (qr > mid) res = res.cnt ? res + query(id << | , mid + , r, ql, qr) : query(id << | , mid + , r, ql, qr);
a[id] = a[id << ] + a[id << | ];
return res;
}
}seg; ll gcd(ll a, ll b) { return b ? gcd(b, a % b) : a; } void Run()
{
for (int i = ; i <= ; ++i) base[i] = base[i - ] + calc(i);
while (scanf("%d%d", &n, &q) != EOF)
{
seg.build(, , n);
char op; int l, r, v;
for (int i = ; i <= q; ++i)
{
scanf(" %c%d%d", &op, &l, &r); ++l;
if (op == 'C')
{
scanf("%d", &v);
seg.update(, , n, l, r, v);
}
else
{
seg.res = seg.query(, , n, l, r);
ll a = seg.res.res, b = seg.res.sze;
ll t = gcd(a, b);
a /= t, b /= t;
printf("%lld/%lld\n", a, b);
}
}
}
} int main()
{
#ifdef LOCAL
freopen("Test.in", "r", stdin);
#endif Run();
return ;
}
3100：单调队列维护左端点，枚举右端点
#include <bits/stdc++.h>
using namespace std; #define N 1000001
int n, res;
int arr[N], pre[N], q[N]; void check(int l, int r, int pos)
{
if (pos > r) return;
if (r - l + == arr[pos]) res = max(res, r - l + );
} void Run()
{
while (scanf("%d", &n) != EOF)
{
res = ;
int l = , r = , L = ;
for (int i = ; i <= n; ++i)
{
scanf("%d", arr + i);
L = max(L, pre[arr[i]] + );
while (l <= r && q[l] <= pre[arr[i]])
{
check(q[l] + , i - , q[l + ]);
++l;
}
pre[arr[i]] = i;
while (l <= r && arr[i] >= arr[q[r]])
{
check(max(L, q[r - ] + ), i - , q[r]);
--r;
}
q[++r] = i;
check(L, i, q[l]);
}
printf("%d\n", res);
}
} int main()
{
#ifdef LOCAL
freopen("Test.in", "r", stdin);
#endif Run();
return ; }
3110：整体二分+线段树
#include <bits/stdc++.h>
using namespace std; #define N 50010
#define ll long long int n, q, m;
ll ans[N]; struct SEG
{
struct node
{
ll cnt, lazy, sum;
node() {}
node(int l, int r)
{
cnt = r - l + ;
lazy = sum = ;
}
}a[N << ]; void pushup(int id)
{
a[id].sum = a[id << ].sum + a[id << | ].sum;
} void pushdown(int id)
{
if (a[id].lazy)
{
int lazy = a[id].lazy; a[id].lazy = ;
a[id << ].lazy += lazy;
a[id << | ].lazy += lazy;
a[id << ].sum += lazy * a[id << ].cnt;
a[id << | ].sum += lazy * a[id << | ].cnt;
}
} void build(int id, int l, int r)
{
a[id] = node(l, r);
if (l == r) return;
int mid = (l + r) >> ;
build(id << , l, mid);
build(id << | , mid + , r);
} void update(int id, int l, int r, int ql, int qr, ll val)
{
if (l >= ql && r <= qr)
{
a[id].lazy += val;
a[id].sum += val * a[id].cnt;
return;
}
pushdown(id);
int mid = (l + r) >> ;
if (ql <= mid) update(id << , l, mid, ql, qr, val);
if (qr > mid) update(id << | , mid + , r, ql, qr, val);
pushup(id);
} ll query(int id, int l, int r, int ql, int qr)
{
if (l >= ql && r <= qr) return a[id].sum;
pushdown(id);
int mid = (l + r) >> ;
ll res = ;
if (ql <= mid) res += query(id << , l, mid, ql, qr);
if (qr > mid) res += query(id << | , mid + , r, ql, qr);
pushup(id);
return res;
}
}segtree; struct QUE
{
int op, x, y, id; ll c;
void scan()
{
scanf("%d%d%d%lld", &op, &x, &y, &c);
if (op == ) id = ++m;
}
}que[N], quel[N], quer[N]; void solve(int ql, int qr, int l, int r)
{
if (ql > qr) return;
if (l == r)
{
for (int i = ql; i <= qr; ++i) if (que[i].op == )
ans[que[i].id] = l;
return;
}
int mid = (l + r) >> , cnt_ql = , cnt_qr = ;
for (int i = ql; i <= qr; ++i)
{
if (que[i].op == )
{
if (que[i].c > mid) segtree.update(, , n, que[i].x, que[i].y, ), quer[++cnt_qr] = que[i];
else quel[++cnt_ql] = que[i];
}
else
{
ll tmp = segtree.query(, , n, que[i].x, que[i].y);
if (tmp < que[i].c) que[i].c -= tmp, quel[++cnt_ql] = que[i];
else quer[++cnt_qr] = que[i];
}
}
for (int i = ; i <= cnt_qr; ++i) if (quer[i].op == ) segtree.update(, , n, quer[i].x, quer[i].y, -);
for (int i = ; i <= cnt_ql; ++i) que[ql + i - ] = quel[i];
for (int i = ; i <= cnt_qr; ++i) que[ql + cnt_ql + i - ] = quer[i];
solve(ql, ql + cnt_ql - , l, mid);
solve(ql + cnt_ql, qr, mid + , r);
} void Run()
{
while (scanf("%d%d", &n, &q) != EOF)
{
for (int i = ; i <= q; ++i) que[i].scan();
segtree.build(, , n);
solve(, q, -N, N);
for (int i = ; i <= m; ++i) printf("%lld\n", ans[i]);
}
} int main()
{
#ifdef LOCAL
freopen("Test.in", "r", stdin);
#endif Run();
return ;
}
3155：硬核线段树
#include <bits/stdc++.h>
using namespace std; #define ll long long
#define N 100010
int n, m;
ll arr[N]; struct SEG
{
ll sum[N << ][];
int cnt[N << ];
void pushup(int id)
{
sum[id][] = sum[id << ][] + sum[id << | ][];
sum[id][] = sum[id << ][] + sum[id << | ][] + cnt[id << | ] * sum[id << ][];
}
void build(int id, int l, int r)
{
cnt[id] = r - l + ;
if (l == r)
{
sum[id][] = sum[id][] = arr[l];
return;
}
int mid = (l + r) >> ;
build(id << , l, mid);
build(id << | , mid + , r);
pushup(id);
}
void update(int id, int l, int r, int pos, ll val)
{
if (l == r)
{
sum[id][] = sum[id][] = val;
return;
}
int mid = (l + r) >> ;
if (pos <= mid) update(id << , l, mid, pos, val);
else update(id << | , mid + , r, pos, val);
pushup(id);
}
ll query(int id, int l, int r, int ql, int qr)
{
if (l >= ql && r <= qr) return sum[id][] * (qr - r) + sum[id][];
int mid = (l + r) >> ;
ll res = ;
if (ql <= mid) res += query(id << , l, mid, ql, qr);
if (qr > mid) res += query(id << | , mid + , r, ql, qr);
return res;
}
}seg; void Run()
{
while (scanf("%d%d", &n, &m) != EOF)
{
for (int i = ; i <= n; ++i) scanf("%lld", arr + i);
seg.build(, , n);
char op[]; int x, y;
for (int i = ; i <= m; ++i)
{
scanf("%s%d", op, &x);
if (op[] == 'Q') printf("%lld\n", seg.query(, , n, , x));
else
{
scanf("%d", &y);
seg.update(, , n, x, y);
}
}
}
} int main()
{
#ifdef LOCAL
freopen("Test.in", "r", stdin);
#endif Run();
return ; }
3173：离线+BIT+二分
#include <bits/stdc++.h>
using namespace std; #define N 100010
int n;
int a[N], b[N], ans[N]; struct BIT_Max
{
int a[N];
void init() { memset(a, , sizeof a); }
void update(int x, int val) { for (; x <= n; x += x & -x) a[x] = max(a[x], val); }
int query(int x) { int res = ; for (; x; x -= x & -x) res = max(res, a[x]); return res; }
}bit_max; struct BIT_sum
{
int a[N];
void init() { memset(a, , sizeof a); }
void update(int x, int val) { for (; x <= n; x += x & -x) a[x] += val; }
int query(int x) { int res = ; for (; x; x -= x & -x) res += a[x]; return res; }
}bit_sum; void Run()
{
while (scanf("%d", &n) != EOF)
{
for (int i = ; i <= n; ++i) scanf("%d", a + i), ++a[i];
bit_sum.init();
for (int i = ; i <= n; ++i) bit_sum.update(i, );
for (int i = n; i >= ; --i)
{
int l = , r = n, pos;
while (r - l >= )
{
int mid = (l + r) >> ;
int num = bit_sum.query(mid);
if (num == a[i])
pos = mid;
if (num >= a[i]) r = mid - ;
else l = mid + ;
}
b[i] = pos;
bit_sum.update(pos, -);
}
bit_max.init();
for (int i = ; i <= n; ++i)
{
int res = bit_max.query(b[i]) + ;
bit_max.update(b[i], res);
ans[i] = bit_max.query(n);
}
for (int i = ; i <= n; ++i) printf("%d\n", ans[i]);
}
} int main()
{
#ifdef LOCAL
freopen("Test.in", "r", stdin);
#endif Run();
return ; }
3262：CDQ分治解决一维，考虑有重复的，将id加入形成四关键字排序使得排序顺序固定，然后前后各扫一遍更新最大答案
#include <bits/stdc++.h>
using namespace std; #define N 200010 int n, k;
int ans[N], cnt[N]; struct node
{
int x, y, z, id;
bool isleft;
void scan(int id)
{
this->id = id;
scanf("%d%d%d", &x, &y, &z);
}
bool operator < (const node &r) const
{
return x == r.x ? (y == r.y ? (z == r.z ? id < r.id : z < r.z) : y < r.y) : x < r.x;
}
bool operator == (const node &r) const { return x == r.x && y == r.y && z == r.z; }
}arr[N], tarr[N]; struct BIT
{
int a[N]; void update(int x, int val)
{
while (x <= k)
{
a[x] += val;
x += x & -x;
}
} int query(int x)
{
int res = ;
while (x)
{
res += a[x];
x -= x & -x;
}
return res;
}
}bit; bool cmp(node a, node b)
{
return a.y == b.y ? (a.z == b.z ? (a.x == b.x ? a.id < b.id : a.x < b.x) : a.z < b.z) : a.y < b.y;
} void CDQ(int l, int r)
{
if (l == r) return;
int mid = (l + r) >> ;
CDQ(l, mid); CDQ(mid + , r);
for (int i = l; i <= r; ++i)
{
tarr[i] = arr[i];
if (i <= mid) tarr[i].isleft = true;
else tarr[i].isleft = false;
}
sort(tarr + l, tarr + r + , cmp);
for (int i = l; i <= r; ++i)
{
if (tarr[i].isleft) bit.update(tarr[i].z, );
else ans[tarr[i].id] += bit.query(tarr[i].z);
}
for (int i = l; i <= r; ++i) if (tarr[i].isleft) bit.update(tarr[i].z, -);
} void Run()
{
while (scanf("%d%d", &n, &k) != EOF)
{
for (int i = ; i <= n; ++i) arr[i].scan(i), ans[i] = ;
sort(arr + , arr + + n);
CDQ(, n);
for (int i = n - ; i >= ; --i) if (arr[i] == arr[i + ])
ans[arr[i].id] = max(ans[arr[i].id], ans[arr[i + ].id]);
for (int i = ; i <= n; ++i) if (arr[i] == arr[i - ])
ans[arr[i].id] = max(ans[arr[i].id], ans[arr[i - ].id]);
for (int i = ; i <= n; ++i) ++cnt[ans[i]];
for (int i = ; i < n; ++i) printf("%d\n", cnt[i]);
}
} int main()
{
#ifdef LOCAL
freopen("Test.in", "r", stdin);
#endif Run();
return ;
}
3295：考虑(t, p, x) 三维偏序问题，分别表示删除的时间，删除的位置，删除的值 用CDQ分治干掉t, 排序干掉p，树状数组干掉x
#include <bits/stdc++.h>
using namespace std; #define N 100010
#define ll long long int n, m, ttm;
int arr[N], pos[N];
ll ans[N];
bool flag[N]; struct QUE
{
int t, p, x;
QUE() {}
QUE(int t, int p, int x) : t(t), p(p), x(x) {}
bool operator < (const QUE &r) const
{
return p < r.p;
}
}q[N], tq[N]; struct BIT
{
int a[N]; void Init()
{
memset(a, , sizeof a);
} void update(int x, int val)
{
while (x <= n)
{
a[x] += val;
x += x & -x;
}
} int query(int x)
{
int res = ;
while (x)
{
res += a[x];
x -= x & -x;
}
return res;
}
}bit; void CDQ(int l, int r)
{
if (l == r) return;
int mid = (l + r) >> ;
CDQ(l, mid); CDQ(mid + , r);
for (int i = l; i <= r; ++i)
{
tq[i] = q[i];
if (i > mid) tq[i].t = ;
}
sort(tq + l, tq + r + );
for (int i = l; i <= r; ++i)
{
if (!tq[i].t) bit.update(tq[i].x, );
else ans[tq[i].t] += bit.query(n) - bit.query(tq[i].x);
}
for (int i = l; i <= r; ++i) if (!tq[i].t) bit.update(tq[i].x, -);
for (int i = r; i >= l; --i)
{
if (!tq[i].t) bit.update(tq[i].x, );
else ans[tq[i].t] += bit.query(tq[i].x);
}
for (int i = l; i <= r; ++i) if (!tq[i].t) bit.update(tq[i].x, -);
} void Run()
{
while (scanf("%d%d", &n, &m) != EOF)
{
ttm = m; bit.Init();
memset(ans, , sizeof ans);
memset(flag, , sizeof flag);
for (int i = ; i <= n; ++i)
{
scanf("%d", arr + i);
pos[arr[i]] = i;
}
for (int i = , x; i <= m; ++i)
{
scanf("%d", &x);
flag[x] = ;
q[i] = QUE(i, pos[x], x);
}
for (int i = ; i <= n; ++i) if (!flag[i])
q[++ttm] = QUE(ttm, pos[i], i);
CDQ(, n);
for (int i = n - ; i >= ; --i) ans[i] += ans[i + ];
for (int i = ; i <= m; ++i) printf("%lld\n", ans[i]);
}
} int main()
{
#ifdef LOCAL
freopen("Test.in", "r", stdin);
#endif Run();
return ;
}
3319：考虑一个黑点产生的影响，即只对它的子树产生影响，再用并查集缩点，这样一个点只会处理一次,加了IO优化才过的，应该不是正解。
#include <bits/stdc++.h>
using namespace std; #define N 1000010
int n, q;
int lp[N], rp[N], pos[N], deep[N], fa[N], cnt;
struct Edge { int to, nx; }edge[N << ];
int head[N], cntedge;
void add(int u, int v) { edge[++cntedge] = Edge{ v, head[u] }; head[u] = cntedge; } void DFS(int u)
{
lp[u] = ++cnt;
for (int it = head[u]; it; it = edge[it].nx)
{
int v = edge[it].to;
if (v == fa[u]) continue;
pos[v] = it >> ;
deep[v] = deep[u] + ;
fa[v] = u;
DFS(v);
}
rp[u] = cnt;
} struct SEG
{
int Max[N << ];
int max(int x, int y)
{
if (deep[x] < deep[y]) return y;
return x;
}
void update(int id, int l, int r, int ql, int qr, int val)
{
if (l >= ql && r <= qr)
{
Max[id] = max(Max[id], val);
return;
}
int mid = (l + r) >> ;
if (ql <= mid) update(id << , l, mid, ql, qr, val);
if (qr > mid) update(id << | , mid + , r, ql, qr, val);
}
int query(int id, int l, int r, int pos)
{
if (l == r) return Max[id];
int mid = (l + r) >> ;
if (pos <= mid) return max(Max[id], query(id << , l, mid, pos));
else return max(Max[id], query(id << | , mid + , r, pos));
}
}seg; int pre[N];
int find(int x) { return pre[x] == ? x : pre[x] = find(pre[x]); } void modify(int u, int v)
{
u = find(u), v = find(v);
while (u != v)
{
if (deep[find(fa[u])] < deep[find(fa[v])])
swap(u, v);
seg.update(, , n, lp[u], rp[u], u);
pre[u] = fa[u]; u = find(u);
}
} namespace FastIO
{
#define BUF_SIZE 10000005
bool IOerror = false;
inline char NC()
{
static char buf[BUF_SIZE], *p1 = buf + BUF_SIZE, *pend = buf + BUF_SIZE;
if (p1 == pend)
{
p1 = buf;
pend = buf + fread(buf, , BUF_SIZE, stdin);
if (pend == p1)
{
IOerror = true;
return -;
}
}
return *p1++;
}
inline bool blank(char ch)
{
return ch == ' ' || ch == '\n' || ch == '\r' || ch == '\t';
}
template <typename T>
inline void read(T &x)
{
char ch;
while (blank(ch = NC()));
if (IOerror)
{
x = -;
return;
}
bool flag = false;
if (ch == '-')
{
flag = true;
ch = NC();
}
if (!isdigit(ch)) while (!isdigit(ch = NC()));
for (x = ch - ''; isdigit(ch = NC()); x = x * + ch - '');
if (flag) x *= -;
}
inline void out(int x)
{
if (x / ) out(x / );
putchar(x % + '');
}
inline void output(int x) { out(x), putchar('\n'); }
#undef BUF_SIZE
}using namespace FastIO; void Run()
{
while (read(n), n != EOF)
{
read(q);
deep[] = ; cntedge = ;
for (int i = , u, v; i < n; ++i)
{
read(u), read(v);
add(u, v); add(v, u);
}
DFS();
for (int i = , op, u, v; i <= q; ++i)
{
read(op), read(v);
if (op == ) output(pos[seg.query(, , n, lp[v])]);
else
{
read(u);
modify(u, v);
}
}
}
} int main()
{
#ifdef LOCAL
freopen("Test.in", "r", stdin);
#endif Run();
return ;
}
3524：主席树
#include <bits/stdc++.h>
using namespace std; #define N 500010
int n, q, m;
int arr[N], brr[N]; void Hash()
{
for (int i = ; i <= n; ++i) brr[i] = arr[i];
sort(brr + , brr + + n);
m = unique(brr + , brr + + n) - brr - ;
for (int i = ; i <= n; ++i) arr[i] = lower_bound(brr + , brr + + m, arr[i]) - brr;
} int T[N];
struct CHAIR
{
#define M N * 40
int a[M], ls[M], rs[M], cnt;
void build(int &id, int l, int r)
{
id = ++cnt;
a[id] = ;
if (l == r) return;
int mid = (l + r) >> ;
build(ls[id], l, mid);
build(rs[id], mid + , r);
}
int update(int pre, int pos)
{
int now = ++cnt, tmp = now;
a[now] = a[pre] + ;
int l = , r = m;
while (l < r)
{
int mid = (l + r) >> ;
if (pos <= mid)
{
ls[now] = ++cnt; rs[now] = rs[pre];
now = ls[now], pre = ls[pre];
r = mid;
}
else
{
ls[now] = ls[pre], rs[now] = ++cnt;
now = rs[now], pre = rs[pre];
l = mid + ;
}
a[now] = a[pre] + ;
}
return tmp;
}
int query(int lt, int rt, int cnt)
{
lt = T[lt], rt = T[rt];
int l = , r = m;
while (l < r)
{
int mid = (l + r) >> ;
int szel = a[ls[rt]] - a[ls[lt]];
int szer = a[rs[rt]] - a[rs[lt]];
if (szel > cnt)
{
lt = ls[lt];
rt = ls[rt];
r = mid;
}
else if (szer > cnt)
{
lt = rs[lt];
rt = rs[rt];
l = mid + ;
}
else
return ;
}
return l;
}
}chair; void Run()
{
while (scanf("%d%d", &n, &q) != EOF)
{
for (int i = ; i <= n; ++i) scanf("%d", arr + i); Hash();
chair.build(T[], , m);
for (int i = ; i <= n; ++i) T[i] = chair.update(T[i - ], arr[i]);
for (int i = , l, r; i <= q; ++i)
{
scanf("%d%d", &l, &r);
printf("%d\n", brr[chair.query(l - , r, (r - l + ) >> )]);
}
}
} int main()
{
#ifdef LOCAL
freopen("Test.in", "r", stdin);
#endif Run();
return ;
}
3578：集合Hash : 给每个点随机Hash权值，所有点权异或起来便是集合Hash值， 插入删除均是异或，然后线段树维护有效人数
#include <bits/stdc++.h>
using namespace std; #define N 100010
int n, m, q, ran;
int Hash[N], loc[N];
map <int, bool> mp; struct SEG
{
int Set[N << ], sum[N << ], peo[N << ], lazy[N << ];
void init()
{
memset(Set, , sizeof Set);
memset(sum, , sizeof sum);
memset(peo, , sizeof peo);
memset(lazy, , sizeof lazy);
}
void pushup(int id) { sum[id] = sum[id << ] + sum[id << | ]; }
void clear(int id, int l, int r)
{
lazy[id] = ; sum[id] = ;
if (l == r)
mp[Set[id]] = ;
}
void pushdown(int id, int l, int r, int mid)
{
if (lazy[id])
{
if (l == r)
{
lazy[id] = ;
return;
}
clear(id << , l, mid);
clear(id << | , mid + , r);
lazy[id] = ;
}
}
void update(int id, int l, int r, int pos, int p, int val)
{
if (l == r)
{
Set[id] ^= p;
peo[id] += val;
sum[id] = (mp.find(Set[id]) == mp.end() ? peo[id] : );
return;
}
int mid = (l + r) >> ;
pushdown(id, l, r, mid);
if (pos <= mid) update(id << , l, mid, pos, p, val);
else update(id << | , mid + , r, pos, p, val);
pushup(id);
} int query(int id, int l, int r, int ql, int qr)
{
int res = ;
if (l >= ql && r <= qr)
{
res = sum[id];
clear(id, l, r);
return res;
}
int mid = (l + r) >> ;
pushdown(id, l, r, mid);
if (ql <= mid) res += query(id << , l, mid, ql, qr);
if (qr > mid) res += query(id << | , mid + , r, ql, qr);
pushup(id);
return res;
}
}seg; void Run()
{
while (scanf("%d%d%d", &n, &m, &q) != EOF)
{
seg.init(); mp.clear();
for (int i = ; i <= n; ++i)
{
ran *= ;
ran += ;
seg.update(, , m, loc[i] = , Hash[i] = ran, );
}
char op; int x, y;
for (int i = ; i <= q; ++i)
{
scanf(" %c%d%d", &op, &x, &y);
if (op == 'C')
{
seg.update(, , m, loc[x], Hash[x], -);
seg.update(, , m, loc[x] = y, Hash[x], );
}
else
printf("%d\n", seg.query(, , m, x, y));
}
}
} int main()
{
#ifdef LOCAL
freopen("Test.in", "r", stdin);
#endif Run();
return ;
}
3589：可持久化线段树+树剖
#include <bits/stdc++.h>
using namespace std; #define N 200010
#define ll long long
ll const MOD = (ll)1ll << ;
int n, q;
struct Edge { int to, nx; }edge[N << ];
int head[N], cntedge;
void addedge(int u, int v) { edge[++cntedge] = Edge{ v, head[u] }; head[u] = cntedge; }
int p[N], lp[N], rp[N], sze[N], son[N], fa[N], deep[N], top[N], cntdfs; void DFS(int u)
{
sze[u] = ;
for (int it = head[u]; ~it; it = edge[it].nx)
{
int v = edge[it].to;
if (v == fa[u]) continue;
deep[v] = deep[u] + ;
fa[v] = u;
DFS(v); sze[u] += sze[v];
if (son[u] == - || sze[v] > sze[son[u]]) son[u] = v;
}
} void getpos(int u, int sp)
{
top[u] = sp;
p[u] = ++cntdfs;
lp[u] = cntdfs;
if (son[u] == -)
{
rp[u] = cntdfs;
return;
}
getpos(son[u], sp);
for (int it = head[u]; ~it; it = edge[it].nx)
{
int v = edge[it].to;
if (v == fa[u] || v == son[u]) continue;
getpos(v, v);
}
rp[u] = cntdfs;
} int T[];
struct SEG
{
#define M N * 60
int cnt;
struct node
{
int ls, rs, pre;
ll sum, lazy;
node() {}
node(int ls, int rs, int pre, ll sum, ll lazy) : ls(ls), rs(rs), pre(pre), sum(sum), lazy(lazy) {}
}a[M];
void pushup(int id)
{
int ls = a[id].ls, rs = a[id].rs;
a[id].sum = (a[ls].sum + a[rs].sum) % MOD;
}
void createson(int &now, int pre)
{
now = ++cnt;
a[now] = node(-, -, pre, , -);
return;
}
void pushdown(int id, int l, int r)
{
if (a[id].lazy == ) return;
int mid = (l + r) >> ;
if (a[id].ls == - || a[id].rs == -)
{
int pre = a[id].pre;
createson(a[id].ls, a[pre].ls);
createson(a[id].rs, a[pre].rs);
}
int ls = a[id].ls, rs = a[id].rs;
if (a[id].lazy == -)
{
a[id].lazy = ;
a[ls].lazy = a[rs].lazy = -;
a[ls].sum = a[rs].sum = ;
return;
}
ll lazy = a[id].lazy; a[id].lazy = ;
a[ls].lazy = (a[ls].lazy + lazy) % MOD; a[ls].sum = (a[ls].sum + lazy * (mid - l + ) % MOD) % MOD;
a[rs].lazy = (a[rs].lazy + lazy) % MOD; a[rs].sum = (a[rs].sum + lazy * (r - mid) % MOD) % MOD;
}
void build(int &id, int l, int r)
{
id = ++cnt;
a[id] = node(-, -, -, , );
if (l == r) return;
int mid = (l + r) >> ;
build(a[id].ls, l, mid);
build(a[id].rs, mid + , r);
}
void update(int id, int l, int r, int ql, int qr, ll val)
{
if (l >= ql && r <= qr)
{
a[id].lazy = (a[id].lazy + val) % MOD;
a[id].sum = (a[id].sum + val * (r - l + ) % MOD) % MOD;
return;
}
pushdown(id, l, r);
int mid = (l + r) >> ;
if (ql <= mid) update(a[id].ls, l, mid, ql, qr, val);
if (qr > mid) update(a[id].rs, mid + , r, ql, qr, val);
pushup(id);
}
void update(int &now, int pre, int l, int r, int ql, int qr, ll val)
{
now = ++cnt;
a[now] = node(-, -, pre, a[pre].sum, a[pre].lazy);
if (l >= ql && r <= qr)
{
a[now].lazy = -;
a[now].sum = ;
return;
}
pushdown(pre, l, r);
int mid = (l + r) >> ;
if (ql <= mid) update(a[now].ls, a[pre].ls, l, mid, ql, qr, val);
else a[now].ls = a[pre].ls;
if (qr > mid) update(a[now].rs, a[pre].rs, mid + , r, ql, qr, val);
else a[now].rs = a[pre].rs;
pushup(now);
}
ll query(int id, int l, int r, int ql, int qr)
{
if (l >= ql && r <= qr) return a[id].sum;
pushdown(id, l, r);
int mid = (l + r) >> ;
ll res = ;
if (ql <= mid) res = (res + query(a[id].ls, l, mid, ql, qr)) % MOD;
if (qr > mid) res = (res + query(a[id].rs, mid + , r, ql, qr)) % MOD;
pushup(id);
return res;
}
}seg; ll query(int u, int v, int now)
{
ll res = ;
while (top[u] != top[v])
{
if (deep[top[u]] < deep[top[v]]) swap(u, v);
res = (res + seg.query(now, , n, p[top[u]], p[u])) % MOD;
u = fa[top[u]];
}
if (deep[u] > deep[v]) swap(u, v);
res = (res + seg.query(now, , n, p[u], p[v])) % MOD;
return res;
} void update(int u, int v, int &now, int pre)
{
while (top[u] != top[v])
{
if (deep[top[u]] < deep[top[v]]) swap(u, v);
seg.update(now, pre, , n, p[top[u]], p[u], );
pre = now;
u = fa[top[u]];
}
if (deep[u] > deep[v]) swap(u, v);
seg.update(now, pre, , n, p[u], p[v], );
} void init()
{
memset(head, -, sizeof head);
memset(son, -, sizeof son);
cntedge = ;
cntdfs = ;
seg.cnt = ;
seg.build(T[], , n);
} void Run()
{
while (scanf("%d", &n) != EOF)
{
init();
for (int i = , u, v; i < n; ++i)
{
scanf("%d%d", &u, &v);
addedge(u, v);
addedge(v, u);
}
DFS(); getpos(, );
scanf("%d", &q);
for (int i = , op; i <= q; ++i)
{
scanf("%d", &op);
if (op == )
{
int u; ll x;
scanf("%d%lld", &u, &x);
if (x == ) continue;
seg.update(T[], , n, lp[u], rp[u], x);
}
else
{
int k, u, v;
scanf("%d", &k);
ll res = ;
int tmp = seg.cnt;
for (int j = ; j < k; ++j)
{
scanf("%d%d", &u, &v);
res = (res + query(u, v, T[j])) % MOD;
T[j + ] = ;
if (j != k - ) update(u, v, T[j + ], T[j]);
}
printf("%lld\n", res);
seg.cnt = tmp;
}
}
}
} int main()
{
#ifdef LOCAL
freopen("Test.in", "r", stdin);
#endif Run();
return ;
}
3626：差分+离线+树剖
#include <bits/stdc++.h>
using namespace std; #define N 50010
int n, q;
vector <int> G[N];
struct qnode { int root, id, vis; };
vector <qnode> que[N];
int ans[N];
int p[N], sze[N], son[N], top[N], deep[N], fa[N], cnt; void DFS(int u)
{
sze[u] = ;
for (int i = , len = G[u].size(); i < len; ++i)
{
int v = G[u][i];
deep[v] = deep[u] + ;
fa[v] = u;
DFS(v); sze[u] += sze[v];
if (son[u] == - || sze[v] > sze[son[u]]) son[u] = v;
}
} void getpos(int u, int sp)
{
top[u] = sp;
p[u] = ++cnt;
if (son[u] == -) return;
getpos(son[u], sp);
for (int i = , len = G[u].size(); i < len; ++i)
{
int v = G[u][i];
if (v == son[u]) continue;
getpos(v, v);
}
} struct SEG
{
int sum[N << ], lazy[N << ];
void pushup(int id) { sum[id] = sum[id << ] + sum[id << | ]; }
void init()
{
memset(sum, , sizeof sum);
memset(lazy, , sizeof lazy);
}
void pushdown(int id, int l, int r)
{
if (!lazy[id]) return;
lazy[id << ] += lazy[id];
lazy[id << | ] += lazy[id];
int mid = (l + r) >> ;
sum[id << ] += lazy[id] * (mid - l + );
sum[id << | ] += lazy[id] * (r - mid);
lazy[id] = ;
}
void update(int id, int l, int r, int ql, int qr)
{
if (l >= ql && r <= qr)
{
sum[id] += (r - l + );
++lazy[id];
return;
}
pushdown(id, l, r);
int mid = (l + r) >> ;
if (ql <= mid) update(id << , l, mid, ql, qr);
if (qr > mid) update(id << | , mid + , r, ql, qr);
pushup(id);
}
int query(int id, int l, int r, int ql, int qr)
{
if (l >= ql && r <= qr) return sum[id];
pushdown(id, l, r);
int mid = (l + r) >> ;
int res = ;
if (ql <= mid) res += query(id << , l, mid, ql, qr);
if (qr > mid) res += query(id << | , mid + , r, ql, qr);
pushup(id);
return res;
}
}seg; void update(int u)
{
while (top[u] != )
{
seg.update(, , n, p[top[u]], p[u]);
u = fa[top[u]];
}
seg.update(, , n, p[], p[u]);
} int query(int u)
{
int res = ;
while (top[u] != )
{
res += seg.query(, , n, p[top[u]], p[u]);
u = fa[top[u]];
}
res += seg.query(, , n, p[], p[u]);
return res;
} void init()
{
for (int i = ; i <= n; ++i) G[i].clear(), que[i].clear();
memset(ans, , sizeof ans);
memset(son, -, sizeof son);
seg.init();
cnt = ;
} void Run()
{
while (scanf("%d%d", &n, &q) != EOF)
{
init();
for (int i = , u; i <= n; ++i)
{
scanf("%d", &u); ++u;
G[u].push_back(i);
}
for (int i = , l, r, z; i <= q; ++i)
{
scanf("%d%d%d", &l, &r, &z); ++r; ++z;
que[l].push_back(qnode{ z, i, - });
que[r].push_back(qnode{ z, i, });
}
DFS(); getpos(, );
for (int i = ; i <= n; ++i)
{
update(i);
for (int j = , len = que[i].size(); j < len; ++j)
{
int z = que[i][j].root, vis = que[i][j].vis, id = que[i][j].id;
ans[id] += vis * query(z);
}
}
for (int i = ; i <= q; ++i) printf("%d\n", ans[i] % );
}
} int main()
{
#ifdef LOCAL
freopen("Test.in", "r", stdin);
#endif Run();
return ; }
3694：最短路树上枚举非树边+树剖
#include <bits/stdc++.h>
using namespace std; #define N 4010
#define M 100010
#define INF 0x3f3f3f3f
int n, m; struct Graph
{
struct node
{
int to, nx, w, vis;
node () {}
node(int to, int nx, int w, int vis) : to(to), nx(nx), w(w), vis(vis) {}
}a[M << ]; int head[N], pos;
void init()
{
memset(head, -, sizeof head);
pos = ;
}
void add(int u, int v, int w, int vis)
{
a[++pos] = node(v, head[u], w, vis); head[u] = pos;
a[++pos] = node(u, head[v], w, vis); head[v] = pos;
}
}G[];
#define erp(G, u) for (int it = G.head[u], v = G.a[it].to, w = G.a[it].w, vis = G.a[it].vis; ~it; it = G.a[it].nx, v = G.a[it].to, w = G.a[it].w, vis = G.a[it].vis) int fa[N], dis[N], deep[N], sze[N], son[N], top[N], p[N], fp[N], cnt;
void DFS(int u)
{
sze[u] = ;
erp(G[], u) if (v != fa[u])
{
fa[v] = u;
dis[v] = dis[u] + w;
deep[v] = deep[u] + ;
DFS(v); sze[u] += sze[v];
if (!son[u] || sze[v] > sze[son[u]]) son[u] = v;
}
} void getpos(int u, int sp)
{
top[u] = sp;
p[u] = ++cnt;
fp[cnt] = u;
if (!son[u]) return;
getpos(son[u], sp);
erp(G[], u) if (v != fa[u] && v != son[u])
getpos(v, v);
} struct SEG
{
int Min[N << ];
void build(int id, int l, int r)
{
Min[id] = INF;
if (l == r) return;
int mid = (l + r) >> ;
build(id << , l, mid);
build(id << | , mid + , r);
}
void update(int id, int l, int r, int ql, int qr, int val)
{
if (l >= ql && r <= qr)
{
Min[id] = min(Min[id], val);
return;
}
int mid = (l + r) >> ;
if (ql <= mid) update(id << , l, mid, ql, qr, val);
if (qr > mid) update(id << | , mid + , r, ql, qr, val);
}
int query(int id, int l, int r, int pos)
{
if (l == r) return Min[id];
int mid = (l + r) >> ;
int res = Min[id];
if (pos <= mid) res = min(res, query(id << , l, mid, pos));
else res = min(res, query(id << | , mid + , r, pos));
return res;
}
}seg; int querylca(int u, int v)
{
while (top[u] != top[v])
{
if (deep[top[u]] < deep[top[v]]) swap(u, v);
u = fa[top[u]];
}
if (deep[u] > deep[v]) swap(u, v);
return u;
} void update(int u, int v, int val)
{
if (u == v) return;
while (top[u] != top[v])
{
if (deep[top[u]] < deep[top[v]]) swap(u, v);
seg.update(, , n, p[top[u]], p[u], val);
u = fa[top[u]];
}
if (u == v) return;
if (deep[u] > deep[v]) swap(u, v);
seg.update(, , n, p[son[u]], p[v], val);
} void init()
{
memset(son, , sizeof son);
cnt = ;
G[].init(); G[].init();
} void Run()
{
while (scanf("%d%d", &n, &m) != EOF)
{
init();
for (int i = , u, v, w, vis; i <= m; ++i)
{
scanf("%d%d%d%d", &u, &v, &w, &vis);
G[].add(u, v, w, vis);
if (vis) G[].add(u, v, w, vis);
} DFS(); getpos(, ); seg.build(, , n);
for (int i = ; i <= n; ++i)
{
erp(G[], i) if (!vis)
{
int lca = querylca(i, v);
update(i, lca, dis[i] + dis[v] + w);
}
}
for (int i = ; i <= n; ++i)
{
int res = seg.query(, , n, p[i]);
printf("%d%c", res == INF ? - : res - dis[i], " \n"[i == n]);
} }
} int main()
{
#ifdef LOCAL
freopen("Test.in", "r", stdin);
#endif Run();
return ;
}
3744：分块+树状数组+主席树
#include <bits/stdc++.h>
using namespace std; #define N 50010
#define block 250 int n, m, q;
int arr[N], brr[N], f[block + ][N]; struct BIT
{
int a[N];
void init() { memset(a, , sizeof a); }
void update(int x, int val) { for (; x <= m; x += x & -x) a[x] += val; }
int query(int x) { int res = ; for (; x; x -= x & -x) res += a[x]; return res; }
}bit; void Hash()
{
for (int i = ; i <= n; ++i) brr[i] = arr[i];
sort(brr + , brr + + n);
m = unique(brr + , brr + + n) - brr - ;
for (int i = ; i <= n; ++i) arr[i] = lower_bound(brr + , brr + + m, arr[i]) - brr;
} struct CHAIR
{
#define M N * 50
int T[N], L[M], R[M], C[M], cnt;
void init(){ cnt = ; }
int build(int l, int r)
{
int root = cnt++;
C[root] = ;
if (l < r)
{
int mid = (l + r) >> ;
L[root] = build(l, mid);
R[root] = build(mid + , r);
}
return root;
}
int update(int root, int pos)
{
int newroot = cnt++, tmp = newroot;
C[newroot] = C[root] + ;
int l = , r = m;
while (l < r)
{
int mid = (l + r) >> ;
if (pos <= mid)
{
L[newroot] = cnt++; R[newroot] = R[root];
newroot = L[newroot], root = L[root];
r = mid;
}
else
{
L[newroot] = L[root], R[newroot] = cnt++;
newroot = R[newroot], root = R[root];
l = mid + ;
}
C[newroot] = C[root] + ;
}
return tmp;
}
int query(int left, int right, int pos)
{
int res = ;
int l = , r = m;
while (l < r)
{
int mid = (l + r) >> ;
if (pos <= mid)
{
left = L[left];
right = L[right];
r = mid;
}
else
{
res += C[L[right]] - C[L[left]];
left = R[left];
right = R[right];
l = mid + ;
}
}
return res;
}
}chair; void Run()
{
while (scanf("%d", &n) != EOF)
{
for (int i = ; i <= n; ++i) scanf("%d", arr + i); Hash();
for (int i = ; (i - ) * block + <= n; ++i)
{
int st = (i - ) * block + ;
bit.init();
for (int j = st; j <= n; ++j)
{
bit.update(arr[j], );
f[i][j] = f[i][j - ] + (j - st + ) - bit.query(arr[j]);
}
}
chair.T[] = chair.build(, m);
for (int i = ; i <= n; ++i) chair.T[i] = chair.update(chair.T[i - ], arr[i]);
scanf("%d", &q); bit.init();
int res = ;
for (int i = , l, r; i <= q; ++i)
{
scanf("%d%d", &l, &r);
l ^= res, r ^= res;
res = ;
if ((l - ) / block == (r - ) / block)
{
for (int j = l; j <= r; ++j)
{
bit.update(arr[j], );
res += (j - l + ) - bit.query(arr[j]);
}
for (int j = l; j <= r; ++j) bit.update(arr[j], -);
}
else
{
int nx = (l - ) / block + ;
res += f[nx + ][r];
for (int j = l; j <= nx * block; ++j) res += chair.query(chair.T[j], chair.T[r], arr[j]);
}
printf("%d\n", res);
}
}
} int main()
{
#ifdef LOCAL
freopen("Test.in", "r", stdin);
#endif Run();
return ;
}
3809：莫队+分块
#include <bits/stdc++.h>
using namespace std; #define N 100010
#define block 450 int n, q;
int arr[N];
struct qnode
{
int l, r, a, b, id;
void scan(int id) { this->id = id; scanf("%d%d%d%d", &l, &r, &a, &b); }
bool operator < (const qnode &r) const
{
int posl = l / block, posr = r.l / block;
return posl == posr ? this->r < r.r : posl < posr;
}
}que[N * ]; int ans[N * ]; int cnt[N], cntblock[block];
void update(int x, int val)
{
if (val == )
{
if (cnt[arr[x]] == ) ++cntblock[(arr[x] - ) / block];
++cnt[arr[x]];
}
else
{
if (cnt[arr[x]] == ) --cntblock[(arr[x] - ) / block];
--cnt[arr[x]];
}
} int query(int l, int r)
{
int posl = (l - ) / block, posr = (r - ) / block;
int res = ;
if (posl == posr)
{
for (int i = l; i <= r; ++i) if (cnt[i])
++res;
}
else
{
for (int i = l; i <= (posl + ) * block; ++i) if (cnt[i])
++res;
for (int i = posl + ; i < posr; ++i)
res += cntblock[i];
for (int i = posr * block + ; i <= r; ++i) if (cnt[i])
++res;
}
return res;
} void Run()
{
while (scanf("%d%d", &n, &q) != EOF)
{
for (int i = ; i <= n; ++i) scanf("%d", arr + i);
for (int i = ; i <= q; ++i) que[i].scan(i);
sort(que + , que + + q);
memset(cnt, , sizeof cnt);
memset(cntblock, , sizeof cntblock);
for (int i = , l = , r = ; i <= q; ++i)
{
for (; r < que[i].r; ++r) update(r + , );
for (; r > que[i].r; --r) update(r, -);
for (; l < que[i].l; ++l) update(l, -);
for (; l > que[i].l; --l) update(l - , );
ans[que[i].id] = query(que[i].a, que[i].b);
}
for (int i = ; i <= q; ++i) printf("%d\n", ans[i]);
}
} int main()
{
#ifdef LOCAL
freopen("Test.in", "r", stdin);
#endif Run();
return ;
}
3910：树剖
#include <bits/stdc++.h>
using namespace std; #define ll long long
#define N 500010 int n, q, st;
vector <int> G[N];
int arr[N]; struct SEG
{
struct node
{
int l, r, vis, lazy;
node() {}
node(int l, int r)
{
this->l = l;
this->r = r;
vis = lazy = ;
}
}a[N << ];
void pushdown(int id)
{
if (a[id].lazy)
{
a[id].lazy = ;
a[id << ].vis = ;
a[id << ].lazy = ;
a[id << | ].vis = ;
a[id << | ].lazy = ;
}
}
void build(int id, int l, int r)
{
a[id] = node(l, r);
if (l == r) return;
int mid = (l + r) >> ;
build(id << , l, mid);
build(id << | , mid + , r);
}
void update(int id, int l, int r)
{
if (a[id].l >= l && a[id].r <= r)
{
a[id].vis = ;
a[id].lazy = ;
return;
}
pushdown(id);
int mid = (a[id].l + a[id].r) >> ;
if (l <= mid) update(id << , l, r);
if (r > mid) update(id << | , l, r);
}
int query(int id, int pos)
{
if (a[id].l == a[id].r) return a[id].vis;
pushdown(id);
int mid = (a[id].l + a[id].r) >> ;
return (pos <= mid ? query(id << , pos) : query(id << | , pos));
}
}seg; int p[N], fp[N], sze[N], son[N], top[N], fa[N], deep[N], cnt;
void DFS(int u)
{
sze[u] = ;
for (int i = , v, len = G[u].size(); i < len; ++i)
{
v = G[u][i];
if (v != fa[u])
{
fa[v] = u;
deep[v] = deep[u] + ;
DFS(v);
sze[u] += sze[v];
if (son[u] == - || sze[v] > sze[son[u]]) son[u] = v;
}
}
} void getpos(int u, int sp)
{
top[u] = sp;
p[u] = ++cnt;
fp[cnt] = u;
if (son[u] == -) return;
getpos(son[u], sp);
for (int i = , v, len = G[u].size(); i < len; ++i)
{
v = G[u][i];
if (v != fa[u] && v != son[u])
getpos(v, v);
}
} int modify(int u, int v)
{
int fu = top[u], fv = top[v];
while (fu != fv)
{
if (deep[fu] < deep[fv])
{
swap(fu, fv);
swap(u, v);
}
seg.update(, p[fu], p[u]);
u = fa[fu]; fu = top[u];
}
if (u == v) return u;
if (deep[u] > deep[v]) swap(u, v);
seg.update(, p[u], p[v]);
return u;
} void Run()
{
while (scanf("%d%d%d", &n, &q, &st) != EOF)
{
seg.build(, , n);
memset(son, -, sizeof son);
cnt = ;
for (int i = ; i <= n; ++i) G[i].clear();
for (int i = , u, v; i < n; ++i)
{
scanf("%d%d", &u, &v);
G[u].push_back(v);
G[v].push_back(u);
}
for (int i = ; i <= q; ++i) scanf("%d", arr + i);
DFS(); getpos(, );
ll res = ;
for (int i = ; i <= q; ++i)
{
if (seg.query(, p[arr[i]]) == )
{
int LCA = modify(st, arr[i]);
res += deep[st] + deep[arr[i]] - * deep[LCA];
st = arr[i];
}
}
printf("%lld\n", res);
}
} int main()
{
#ifdef LOCAL
freopen("Test.in", "r", stdin);
#endif Run();
return ; }
4012：树剖+可持久化线段树（标记永久化）
#include <bits/stdc++.h>
using namespace std; #define N 150010
#define ll long long
#define pii pair <int, int>
int n, q, a[N], age[N]; ll A;
ll sum[N]; struct Graph
{
struct node
{
int to, nx; int w;
node() {}
node(int to, int nx, int w) : to(to), nx(nx), w(w) {}
}a[N << ];
int head[N], pos;
void Init() { memset(head, , sizeof head); pos = ; }
void add(int u, int v, int w)
{
a[++pos] = node(v, head[u], w); head[u] = pos;
a[++pos] = node(u, head[v], w); head[v] = pos;
}
}G;
#define erp(u) for (int it = G.head[u], v = G.a[it].to, w = G.a[it].w; it; it = G.a[it].nx, v = G.a[it].to, w = G.a[it].w) ll dis[N], arr[N], prefix[N];
int p[N], fp[N], fa[N], deep[N], sze[N], son[N], top[N], cnt;
void DFS(int u)
{
sze[u] = ;
erp(u) if (v != fa[u])
{
fa[v] = u;
deep[v] = deep[u] + ;
dis[v] = dis[u] + w;
arr[v] = w;
DFS(v); sze[u] += sze[v];
if (!son[u] || sze[v] > sze[son[u]]) son[u] = v;
}
} void getpos(int u, int sp)
{
top[u] = sp;
p[u] = ++cnt;
fp[cnt] = u;
if (!son[u]) return;
getpos(son[u], sp);
erp(u) if (v != fa[u] && v != son[u])
getpos(v, v);
} int T[N];
struct SEG
{
#define M N * 75
struct node
{
int ls, rs; ll lazy, sum;
node() {}
node (int ls, int rs, ll lazy, ll sum) : ls(ls), rs(rs), lazy(lazy), sum(sum) {}
}a[M]; int cnt;
void build(int &now, int l, int r)
{
now = ++cnt;
a[now] = node(-, -, , );
if (l == r) return;
int mid = (l + r) >> ;
build(a[now].ls, l, mid);
build(a[now].rs, mid + , r);
}
void update(int &now, int pre, int l, int r, int ql, int qr)
{
now = ++cnt;
a[now] = a[pre];
a[now].sum += prefix[qr] - prefix[ql - ];
if (l >= ql && r <= qr)
{
++a[now].lazy;
return;
}
int mid = (l + r) >> ;
if (ql <= mid) update(a[now].ls, a[pre].ls, l, mid, ql, min(mid, qr));
if (qr > mid) update(a[now].rs, a[pre].rs, mid + , r, max(mid + , ql), qr);
}
ll query(int lt, int rt, int l, int r, int ql, int qr)
{
if (l >= ql && r <= qr) return a[rt].sum - a[lt].sum;
int mid = (l + r) >> ;
ll res = (a[rt].lazy - a[lt].lazy) * (prefix[qr] - prefix[ql - ]);
if (ql <= mid) res += query(a[lt].ls, a[rt].ls, l, mid, ql, min(mid, qr));
if (qr > mid) res += query(a[lt].rs, a[rt].rs, mid + , r, max(mid + , ql), qr);
return res;
}
}seg; void update(int u, int v, int &now, int pre)
{
now = pre;
while (top[u] != top[v])
{
if (deep[top[u]] < deep[top[v]]) swap(u, v);
seg.update(now, pre, , n, p[top[u]], p[u]);
pre = now;
u = fa[top[u]];
}
if (u == v) return;
if (deep[u] > deep[v]) swap(u, v);
seg.update(now, pre, , n, p[son[u]], p[v]);
} ll query(int u, int v, int lt, int rt)
{
ll res = ;
while (top[u] != top[v])
{
if (deep[top[u]] < deep[top[v]]) swap(u, v);
res += seg.query(lt, rt, , n, p[top[u]], p[u]);
u = fa[top[u]];
}
if (u == v) return res;
if (deep[u] > deep[v]) swap(u, v);
return res + seg.query(lt, rt, , n, p[son[u]], p[v]);
} bool cmp(int a, int b) { return age[a] < age[b]; } void init()
{
G.Init(); cnt = ; dis[] = ; deep[] = ;
seg.cnt = ; sum[] = ; arr[] = ;
memset(son, , sizeof son);
} void Run()
{
while (scanf("%d%d%lld", &n, &q, &A) != EOF)
{
init();
for (int i = ; i <= n; ++i) scanf("%d", age + i), a[i] = i;
sort(a + , a + + n, cmp);
sort(age + , age + + n);
for (int i = , u, v, w; i < n; ++i)
{
scanf("%d%d%d", &u, &v, &w);
G.add(u, v, w);
}
DFS(); getpos(, );
seg.build(T[], , n);
for (int i = ; i <= n; ++i) prefix[i] = prefix[i - ] + arr[fp[i]];
for (int i = ; i <= n; ++i)
{
update(, a[i], T[i], T[i - ]);
sum[i] = sum[i - ] + dis[a[i]];
}
ll res = ; int u; ll l, r;
for (int i = ; i <= q; ++i)
{
scanf("%d%lld%lld", &u, &l, &r);
l = (l + res) % A;
r = (r + res) % A;
if (l > r) swap(l, r);
int ql = lower_bound(age + , age + + n, l) - age;
int qr = upper_bound(age + , age + + n, r) - age - ;
if (ql > qr) res = ;
else
{
res = sum[qr] - sum[ql - ] + dis[u] * (qr - ql + );
res -= * query(, u, T[ql - ], T[qr]);
}
printf("%lld\n", res); res %= A;
}
}
} int main()
{
Run();
return ;
}
4236：考虑拆成两个等式判断L, R是否满足，再借助map快速找答案
#include <bits/stdc++.h>
using namespace std; #define N 200010
int n, pos[N], J[N], O[N], I[N];
char s[N];
map <int, int> mp[N];
int Hasharr[N], m; void Hash()
{
for (int i = ; i <= n; ++i) Hasharr[i] = pos[i];
sort(Hasharr, Hasharr + + n);
m = unique(Hasharr, Hasharr + + n) - Hasharr;
for (int i = ; i <= n; ++i) pos[i] = lower_bound(Hasharr, Hasharr + + m, pos[i]) - Hasharr;
} void Run()
{
while (scanf("%d", &n) != EOF)
{
scanf("%s", s + );
for (int i = ; i <= n; ++i)
{
J[i] = J[i - ];
O[i] = O[i - ];
I[i] = I[i - ];
if (s[i] == 'J') ++J[i];
else if (s[i] == 'O') ++O[i];
else ++I[i];
}
for (int i = ; i <= n; ++i) pos[i] = J[i] - O[i]; Hash();
int res = ;
for (int i = ; i <= n; ++i)
{
int need = O[i] - I[i];
if (mp[pos[i]].find(need) != mp[pos[i]].end())
res = max(res, i - mp[pos[i]][need]);
else
mp[pos[i]][need] = i;
}
printf("%d\n", res);
}
} int main()
{
#ifdef LOCAL
freopen("Test.in", "r", stdin);
#endif Run();
return ;
}
4260：可持久化trie+DP
#include <bits/stdc++.h>
using namespace std; #define N 400010
int n;
int arr[N], dp[N]; int T[N];
struct TRIE
{
struct node
{
int son[], cnt;
}a[N * ]; int cnt;
void Insert(int &now, int pre, int x)
{
bitset <> b; b = x;
now = ++cnt;
a[now] = a[pre];
int root = now;
for (int i = ; i >= ; --i)
{
a[++cnt] = a[a[root].son[b[i]]];
++a[cnt].cnt;
a[root].son[b[i]] = cnt;
root = cnt;
}
}
int query(int lt, int rt, int x)
{
bitset <> b; b = x;
lt = T[lt], rt = T[rt];
int res = ;
for (int i = ; i >= ; --i)
{
int id = b[i] ^ ;
bool flag = true;
if (a[a[rt].son[id]].cnt - a[a[lt].son[id]].cnt <= )
{
flag = false;
id ^= ;
}
if (flag) res += << i;
lt = a[lt].son[id];
rt = a[rt].son[id];
}
return res;
}
}trie; void Run()
{
while (scanf("%d", &n) != EOF)
{
for (int i = ; i <= n; ++i) scanf("%d", arr + i);
for (int i = ; i <= n; ++i) arr[i] ^= arr[i - ];
trie.cnt = ; trie.Insert(T[], T[], );
for (int i = ; i <= n; ++i) trie.Insert(T[i], T[i - ], arr[i]);
for (int i = n; i >= ; --i) dp[i] = max(dp[i + ], trie.query(i - , n, arr[i - ]));
int res = ;
for (int i = ; i <= n; ++i)
res = max(res, trie.query(, i, arr[i]) + dp[i + ]);
printf("%d\n", res);
}
} int main()
{
#ifdef LOCAL
freopen("Test.in", "r", stdin);
#endif Run();
return ;
}
4291：考虑如何构造偶数
#include <bits/stdc++.h>
using namespace std; #define ll long long
#define N 1000010 int n; void Run()
{
while (scanf("%d", &n) != EOF)
{
ll res = ; int cnt = , Min = 0x3f3f3f3f;
for (int i = , num; i <= n; ++i)
{
scanf("%d", &num);
if (num & )
{
++cnt;
Min = min(Min, num);
}
res += num;
}
if (cnt & ) res -= Min;
if (res == )
{
puts("NIESTETY");
continue;
}
printf("%lld\n", res); }
} int main()
{
#ifdef LOCAL
freopen("Test.in", "r", stdin);
#endif Run();
return ; }
4300：对每一位考虑，$b[i] And b[i - 1] != 0$ 即至少有一位都是1
#include <bits/stdc++.h>
using namespace std; #define N 100010
int n, arr[N], Max[]; void Run()
{
while (scanf("%d", &n) != EOF)
{
for (int i = ; i <= n; ++i) scanf("%d", arr + i);
memset(Max, , sizeof Max);
int ans = ;
for (int i = ; i <= n; ++i)
{
bitset <> b; b = arr[i];
int res = ;
for (int j = ; j >= ; --j) if (b[j])
res = max(res, Max[j]);
ans = max(res + , ans);
for (int j = ; j >= ; --j) if (b[j])
Max[j] = max(Max[j], res + );
}
printf("%d\n", ans);
}
} int main()
{
#ifdef LOCAL
freopen("Test.in", "r", stdin);
#endif Run();
return ;
}
4326：二分+树剖+线段树
#include <bits/stdc++.h>
using namespace std; #define ll long long
#define N 300010
#define pii pair <int, int>
int n, m;
vector <pii> G[N]; pii que[N];
struct Edge { int u, v; ll w; Edge() {} Edge(int u, int v, ll w) : u(u), v(v), w(w) {} } edge[N];
int p[N], fp[N], fa[N], deep[N], sze[N], son[N], top[N], cnt;
ll dis[N], arr[N]; void DFS(int u)
{
sze[u] = ;
for (int i = , len = G[u].size(); i < len; ++i)
{
int v = G[u][i].first;
if (v == fa[u]) continue;
fa[v] = u;
deep[v] = deep[u] + ;
dis[v] = dis[u] + G[u][i].second;
DFS(v); sze[u] += sze[v];
if (!son[u] || sze[v] > sze[son[u]]) son[u] = v;
}
} void getpos(int u, int sp)
{
top[u] = sp;
p[u] = ++cnt;
fp[cnt] = u;
if (!son[u]) return;
getpos(son[u], sp);
for (int i = , len = G[u].size(); i < len; ++i)
{
int v = G[u][i].first;
if (v == fa[u] || v == son[u]) continue;
getpos(v, v);
}
} struct SEG
{
int a[N << ], lazy[N << ];
void Init()
{
memset(a, , sizeof a);
memset(lazy, , sizeof lazy);
}
void pushdown(int id, int l, int r, int mid)
{
if (!lazy[id]) return;
lazy[id << ] += lazy[id];
a[id << ] += lazy[id] * (mid - l + );
lazy[id << | ] += lazy[id];
a[id << | ] += lazy[id] * (r - mid);
lazy[id] = ;
}
void pushup(int id) { a[id] = a[id << ] + a[id << | ]; }
void update(int id, int l, int r, int ql, int qr)
{
if (l >= ql && r <= qr)
{
a[id] += r - l + ;
++lazy[id];
return;
}
int mid = (l + r) >> ;
pushdown(id, l, r, mid);
if (ql <= mid) update(id << , l, mid, ql, qr);
if (qr > mid) update(id << | , mid + , r, ql, qr);
pushup(id);
}
int query(int id, int l, int r, int pos)
{
if (l == r) return a[id];
int mid = (l + r) >> ;
pushdown(id, l, r, mid);
int res = ;
if (pos <= mid) res = query(id << , l, mid, pos);
else res = query(id << | , mid + , r, pos);
pushup(id);
return res;
}
}seg; int querylca(int u, int v)
{
while (top[u] != top[v])
{
if (deep[top[u]] < deep[top[v]]) swap(u, v);
u = fa[top[u]];
}
if (deep[u] > deep[v]) swap(u, v);
return u;
} void update(int u, int v)
{
while (top[u] != top[v])
{
if (deep[top[u]] < deep[top[v]]) swap(u, v);
seg.update(, , n, p[top[u]], p[u]);
u = fa[top[u]];
}
if (u == v) return;
if (deep[u] > deep[v]) swap(u, v);
seg.update(, , n, p[son[u]], p[v]);
} bool check(ll x)
{
seg.Init(); vector <ll> vec;
for (int i = ; i <= m; ++i)
{
int u = que[i].first, v = que[i].second;
ll tot = dis[u] + dis[v] - * dis[querylca(u, v)];
if (tot <= x) continue;
update(u, v);
vec.push_back(tot);
}
ll Max = -; int tot = vec.size();
if (tot == ) return true;
for (int i = ; i <= n; ++i) if (seg.query(, , n, i) == tot)
Max = max(Max, arr[fp[i]]);
if (Max == -) return false;
for (int i = ; i < tot; ++i)
if (vec[i] - Max > x) return false;
return true;
} void Run()
{
while (scanf("%d%d", &n, &m) != EOF)
{
ll tot = ;
for (int i = , u, v, w; i < n; ++i)
{
scanf("%d%d%d", &u, &v, &w);
edge[i] = Edge(u, v, w);
G[u].push_back(pii(v, w));
G[v].push_back(pii(u, w));
tot += w;
}
for (int i = ; i <= m; ++i)
scanf("%d%d", &que[i].first, &que[i].second);
DFS(); getpos(, );
for (int i = ; i < n; ++i)
{
if (fa[edge[i].v] != edge[i].u) swap(edge[i].u, edge[i].v);
arr[edge[i].v] = edge[i].w;
}
ll l = , r = tot, res = tot;
while (r - l >= )
{
ll mid = (l + r) >> ;
if (check(mid))
{
res = mid;
r = mid - ;
}
else
l = mid + ;
}
printf("%lld\n", res);
}
} int main()
{
#ifdef LOCAL
freopen("Test.in", "r", stdin);
#endif Run();
return ;
}
4397：前缀
#include <bits/stdc++.h>
using namespace std; #define N 100010
int n, q;
int sum[][N]; void Run()
{
while (scanf("%d%d", &n, &q) != EOF)
{
memset(sum, , sizeof sum);
for (int i = , x; i <= n; ++i)
{
scanf("%d", &x);
++sum[x - ][i];
for (int j = ; j < ; ++j)
sum[j][i] += sum[j][i - ];
}
for (int i = , l, r; i <= q; ++i)
{
scanf("%d%d", &l, &r);
for (int j = ; j < ; ++j)
printf("%d%c", sum[j][r] - sum[j][l - ], " \n"[j == ]);
}
}
} int main()
{
#ifdef LOCAL
freopen("Test.in", "r", stdin);
#endif Run();
return ;
}
4423：对偶图+并查集 建图需要多建一圈
#include <bits/stdc++.h>
using namespace std; #define N 1510
int n, q, S, ans;
int pos[N][N], pre[N * N]; int find(int x) { return pre[x] == ? x : pre[x] = find(pre[x]); } void Run()
{
while (scanf("%d%d", &n, &q) != EOF)
{
memset(pre, , sizeof pre);
S = (n - ) * (n - ) + ;
for (int i = ; i <= n + ; ++i) for (int j = ; j <= n + ; ++j) pos[i][j] = S;
for (int i = , tot = ; i <= n; ++i) for (int j = ; j <= n; ++j) pos[i][j] = ++tot;
char op; int a, b, x, y; ans = ;
while (q--)
{
scanf("%d%d %c", &a, &b, &op);
if (ans) scanf("%d%d %c", &a, &b, &op);
if (op == 'N') x = pos[a][b + ], y = pos[a + ][b + ];
else x = pos[a + ][b], y = pos[a + ][b + ];
if (!ans) scanf("%d%d %c", &a, &b, &op);
int fx = find(x), fy = find(y);
ans = fx == fy;
if (!ans) pre[fx] = fy;
puts(ans ? "NIE" : "TAK");
}
}
} int main()
{
#ifdef LOCAL
freopen("Test.in", "r", stdin);
#endif Run();
return ;
}
4448：可持久化线段树+树链剖分
#include <bits/stdc++.h>
using namespace std; #define N 200010
#define pii pair <int, int>
int n, q;
vector <int> G[N];
int p[N], fp[N], sze[N], fa[N], deep[N], top[N], son[N], cnt; void DFS(int u)
{
sze[u] = ;
for (int i = , len = G[u].size(); i < len; ++i)
{
int v = G[u][i];
if (v == fa[u]) continue;
fa[v] = u; deep[v] = deep[u] + ;
DFS(v); sze[u] += sze[v];
if (!son[u] || sze[v] > sze[son[u]]) son[u] = v;
}
} void getpos(int u, int sp)
{
top[u] = sp;
p[u] = ++cnt;
fp[cnt] = u;
if (!son[u]) return;
getpos(son[u], sp);
for (int i = , len = G[u].size(); i < len; ++i)
{
int v = G[u][i];
if (v == fa[u] || v == son[u]) continue;
getpos(v, v);
}
} int T[N];
struct SEG
{
#define M N * 40
int a[M], ls[M], rs[M], cnt;
void build(int &id, int l, int r)
{
id = ++cnt;
a[id] = ;
if (l == r) return;
int mid = (l + r) >> ;
build(ls[id], l, mid);
build(rs[id], mid + , r);
}
void pushup(int id) { a[id] = a[ls[id]] + a[rs[id]]; }
void update(int &now, int pre, int l, int r, int pos)
{
now = ++cnt;
a[now] = a[pre]; ls[now] = ls[pre]; rs[now] = rs[pre];
if (l == r)
{
++a[now];
return;
}
int mid = (l + r) >> ;
if (pos <= mid) update(ls[now], ls[pre], l, mid, pos);
else update(rs[now], rs[pre], mid + , r, pos);
pushup(now);
}
int query(int now, int l, int r, int ql, int qr)
{
if (l >= ql && r <= qr) return a[now];
int mid = (l + r) >> ;
int res = ;
if (ql <= mid) res += query(ls[now], l, mid, ql, qr);
if (qr > mid) res += query(rs[now], mid + , r, ql, qr);
return res;
}
}seg; pii query(int u, int v, int c)
{
int res = ;
while (top[u] != top[v])
{
if (deep[top[u]] < deep[top[v]])
swap(u, v);
res += seg.query(T[c], , n, p[top[u]], p[u]);
u = fa[top[u]];
}
if (deep[u] > deep[v]) swap(u, v);
res += seg.query(T[c], , n, p[u], p[v]);
return pii(u, res);
} void Run()
{
while (scanf("%d", &n) != EOF)
{
for (int i = , u; i <= n; ++i)
{
scanf("%d", &u);
if (u)
{
G[u].push_back(i);
G[i].push_back(u);
}
}
DFS(); getpos(, );
seg.build(T[], , n);
scanf("%d", &q);
int op, x, y, c;
for (int i = ; i <= q; ++i)
{
scanf("%d%d", &op, &x);
if (op == ) seg.update(T[i], T[i - ], , n, p[x]);
else
{
T[i] = T[i - ];
scanf("%d%d", &y, &c);
pii res = query(x, y, max(, i - c - ));
res.first = deep[x] + deep[y] - * deep[res.first] + ;
printf("%d %d\n", res.first, res.second);
}
}
}
} int main()
{
#ifdef LOCAL
freopen("Test.in", "r", stdin);
#endif Run();
return ;
}
4551：树剖
#include <bits/stdc++.h>
using namespace std; #define ll long long
#define N 100010 int n, q;
vector <int> G[N]; struct SEG
{
int Max[N << ];
void pushup(int id) { Max[id] = max(Max[id << ], Max[id << | ]); }
void build(int id, int l, int r)
{
Max[id] = ;
if (l == r) return;
int mid = (l + r) >> ;
build(id << , l, mid);
build(id << | , mid + , r);
}
void update(int id, int l, int r, int pos)
{
if (l == r)
{
Max[id] = pos;
return;
}
int mid = (l + r) >> ;
pos <= mid ? update(id << , l, mid, pos) : update(id << | , mid + , r, pos);
pushup(id);
}
int query(int id, int l, int r, int ql, int qr)
{
if (l >= ql && r <= qr) return Max[id];
int mid = (l + r) >> , res = ;
if (ql <= mid) res = max(res, query(id << , l, mid, ql, qr));
if (qr > mid) res = max(res, query(id << | , mid + , r, ql, qr));
return res;
}
}seg; int p[N], fp[N], sze[N], son[N], top[N], fa[N], deep[N], cnt;
void DFS(int u)
{
sze[u] = ;
for (int i = , v, len = G[u].size(); i < len; ++i)
{
v = G[u][i];
if (v != fa[u])
{
fa[v] = u;
deep[v] = deep[u] + ;
DFS(v);
sze[u] += sze[v];
if (son[u] == - || sze[v] > sze[son[u]]) son[u] = v;
}
}
} void getpos(int u, int sp)
{
top[u] = sp;
p[u] = ++cnt;
fp[cnt] = u;
if (son[u] == -) return;
getpos(son[u], sp);
for (int i = , v, len = G[u].size(); i < len; ++i)
{
v = G[u][i];
if (v != fa[u] && v != son[u])
getpos(v, v);
}
} int query(int u, int v)
{
int fu = top[u], fv = top[v];
int res = ;
while (fu != fv)
{
if (deep[fu] < deep[fv])
{
swap(fu, fv);
swap(u, v);
}
res = max(res, seg.query(, , n, p[fu], p[u]));
u = fa[fu]; fu = top[u];
}
if (deep[u] > deep[v]) swap(u, v);
res = max(res, seg.query(, , n, p[u], p[v]));
return res;
} void Run()
{
while (scanf("%d%d", &n, &q) != EOF)
{
seg.build(, , n);
memset(son, -, sizeof son);
cnt = ;
for (int i = ; i <= n; ++i) G[i].clear();
for (int i = , u, v; i < n; ++i)
{
scanf("%d%d", &u, &v);
G[u].push_back(v);
G[v].push_back(u);
}
DFS(); getpos(, );
seg.update(, , n, );
char op;
for (int i = , u; i <= q; ++i)
{
scanf(" %c%d", &op, &u);
if (op == 'Q') printf("%d\n", fp[query(u, )]);
else seg.update(, , n, p[u]);
}
}
} int main()
{
#ifdef LOCAL
freopen("Test.in", "r", stdin);
#endif Run();
return ; }
4552：二分答案+线段树 考虑把 >x 的数标为0，<x 的数标为1
#include <bits/stdc++.h>
using namespace std; #define N 100010
int n, m, q;
int arr[N]; struct qnode
{
int op, l, r;
void scan() { scanf("%d%d%d", &op, &l, &r); }
}que[N]; struct SEG
{
int lazy[N << ], sum[N << ];
void init()
{
memset(lazy, -, sizeof lazy);
memset(sum, , sizeof sum);
}
void pushup(int id) { sum[id] = sum[id << ] + sum[id << | ]; }
void pushdown(int id, int l, int r, int mid)
{
if (lazy[id] == -) return;
lazy[id << ] = lazy[id];
sum[id << ] = lazy[id] * (mid - l + );
lazy[id << | ] = lazy[id];
sum[id << | ] = lazy[id] * (r - mid);
lazy[id] = -;
}
void update(int id, int l, int r, int ql, int qr, int val)
{
if (ql > qr) return;
if (l >= ql && r <= qr)
{
lazy[id] = val;
sum[id] = val * (r - l + );
return;
}
int mid = (l + r) >> ;
pushdown(id, l, r, mid);
if (ql <= mid) update(id << , l, mid, ql, qr, val);
if (qr > mid) update(id << | , mid + , r, ql, qr, val);
pushup(id);
}
int query(int id, int l, int r, int ql, int qr)
{
if (l >= ql && r <= qr) return sum[id];
int mid = (l + r) >> ;
pushdown(id, l, r, mid);
int res = ;
if (ql <= mid) res += query(id << , l, mid, ql, qr);
if (qr > mid) res += query(id << | , mid + , r, ql, qr);
pushup(id);
return res;
}
}seg; bool check(int x)
{
seg.init();
for (int i = ; i <= n; ++i)
seg.update(, , n, i, i, arr[i] > x);
for (int i = ; i <= m; ++i)
{
int l = que[i].l, r = que[i].r;
int cnt_one = seg.query(, , n, l, r), cnt_zero = (r - l + ) - cnt_one;
if (que[i].op == )
{
seg.update(, , n, l, l + cnt_zero - , );
seg.update(, , n, l + cnt_zero, r, );
}
else
{
seg.update(, , n, l, l + cnt_one - , );
seg.update(, , n, l + cnt_one, r, );
}
}
return !seg.query(, , n, q, q);
} void Run()
{
while (scanf("%d%d", &n, &m) != EOF)
{
for (int i = ; i <= n; ++i) scanf("%d", arr + i);
for (int i = ; i <= m; ++i) que[i].scan();
scanf("%d", &q);
int l = , r = n, res = ;
while (r - l >= )
{
int mid = (l + r) >> ;
if (check(mid))
{
res = mid;
r = mid - ;
}
else
l = mid + ;
}
printf("%d\n", res);
}
} int main()
{
#ifdef LOCAL
freopen("Test.in", "r", stdin);
#endif Run();
return ;
}
4553：将一个点拆分成两个，找不等关系，CDQ分治
#include <bits/stdc++.h>
using namespace std; #define N 100010 struct node
{
int v, Max, Min;
void scan()
{
scanf("%d", &v);
Max = Min = v;
}
void update()
{
int tmp;
scanf("%d", &tmp);
Max = max(Max, tmp);
Min = min(Min, tmp);
}
}arr[N]; struct qnode
{
int op, x, y, id;
qnode() {}
qnode(int op, int id, int x, int y) : op(op), id(id), x(x), y(y) {}
bool operator < (const qnode &r) const { return x == r.x ? (y == r.y ? (id == r.id ? op > r.op : id < r.id) : y < r.y) : x < r.x; }
}q[N << ], tq[N << ]; struct BIT
{
int a[N];
void init() { memset(a, , sizeof a); }
void update(int x, int val) { for (; x < N; x += x & -x) a[x] = max(a[x], val); }
int query(int x) { int res(); for (; x; x -= x & -x) res = max(res, a[x]); return res; }
void clear(int x) { for (; x < N; x += x & -x) a[x] = ; }
}bit; int n, m, res;
int dp[N]; void CDQ(int l, int r)
{
if (l >= r) return;
int mid = (l + r) >> ;
CDQ(l, mid);
for (int i = l; i <= r; ++i)
{
tq[i] = q[i];
if (i <= mid)
{
if (tq[i].op == )
tq[i].op = ;
else
tq[i].op = ;
}
}
sort(tq + l, tq + r + );
for (int i = l; i <= r; ++i)
{
if (!tq[i].op) bit.update(tq[i].y, dp[tq[i].id]);
else if (tq[i].op == ) dp[tq[i].id] = max(dp[tq[i].id], bit.query(tq[i].y) + );
}
for (int i = l; i <= r; ++i) if (!tq[i].op) bit.clear(tq[i].y);
CDQ(mid + , r);
} void Run()
{
while (scanf("%d%d", &n, &m) != EOF)
{
bit.init();
for (int i = ; i <= n; ++i) dp[i] = ;
for (int i = ; i <= n; ++i) arr[i].scan();
for (int i = , x; i <= m; ++i)
{
scanf("%d", &x);
arr[x].update();
}
for (int i = ; i <= n; ++i)
{
q[(i << ) - ] = qnode(, i, arr[i].Min, arr[i].v);
q[i << ] = qnode(, i, arr[i].v, arr[i].Max);
}
CDQ(, n << ); res = ;
for (int i = ; i <= n; ++i) res = max(res, dp[i]);
printf("%d\n", res);
}
} int main()
{
#ifdef LOCAL
freopen("Test.in", "r", stdin);
#endif Run();
return ;
}
4999：树链剖分+线段树 （离散化后对每一个x开线段树，动态开点）
#include <bits/stdc++.h>
using namespace std; #define N 100010
#define M 3500010 int n, m, q;
int arr[N], brr[N << ];
vector <int> G[N]; int Get(int x)
{
return lower_bound(brr + , brr + + m, x) - brr;
} struct QUE
{
int op, u, v, x;
void scan()
{
char s[];
scanf("%s", s);
if (s[] == 'Q')
{
op = ;
scanf("%d%d%d", &u, &v, &x);
brr[++m] = x;
}
else
{
op = ;
scanf("%d%d", &u, &x);
brr[++m] = x;
}
}
}que[N << ]; int top[N], num[N], deep[N], fa[N], son[N], p[N], fp[N], pos; void DFS(int u)
{
num[u] = ;
for (int i = , len = G[u].size(); i < len; ++i)
{
int v = G[u][i];
if (v == fa[u]) continue;
deep[v] = deep[u] + ;
fa[v] = u;
DFS(v); num[u] += num[v];
if (son[u] == - || num[v] > num[son[u]])
son[u] = v;
}
} void getpos(int u, int sp)
{
top[u] = sp;
p[u] = ++pos;
fp[pos] = u;
if (son[u] == -) return;
getpos(son[u], sp);
for (int i = , len = G[u].size(); i < len; ++i)
{
int v = G[u][i];
if (v != son[u] && v != fa[u])
getpos(v, v);
}
} struct SEG
{
int T[N << ], lson[M], rson[M], c[M], cnt; void pushup(int id)
{
c[id] = c[lson[id]] + c[rson[id]];
} void update(int &x, int l, int r, int pos, int val)
{
if (!x)
{
x = ++cnt;
lson[x] = rson[x] = c[x] = ;
}
if (l == r)
{
c[x] += val;
return;
}
int mid = (l + r) >> ;
if (pos <= mid) update(lson[x], l, mid, pos, val);
else update(rson[x], mid + , r, pos, val);
pushup(x);
} int query(int x, int l, int r, int ql, int qr)
{
if (l >= ql && r <= qr) return c[x];
int mid = (l + r) >> ;
int res = ;
if (ql <= mid) res += query(lson[x], l, mid, ql, qr);
if (qr > mid) res += query(rson[x], mid + , r, ql, qr);
return res;
} }segtree; int query(int u, int v, int x)
{
int fu = top[u], fv = top[v];
x = segtree.T[x];
int res = ;
while (fu != fv)
{
if (deep[fu] < deep[fv])
{
swap(u, v);
swap(fu, fv);
}
res += segtree.query(x, , n, p[fu], p[u]);
u = fa[fu];
fu = top[u];
}
if (deep[u] > deep[v]) swap(u, v);
res += segtree.query(x, , n, p[u], p[v]);
return res;
} void Run()
{
while (scanf("%d%d", &n, &q) != EOF)
{
m = ; fa[] = ; deep[] = ; pos = ;
memset(son, -, sizeof son);
for (int i = ; i <= n; ++i) scanf("%d", arr + i), brr[++m] = arr[i];
for (int i = , u, v; i < n; ++i)
{
scanf("%d%d", &u, &v);
G[u].push_back(v);
G[v].push_back(u);
} DFS(); getpos(, );
for (int i = ; i <= q; ++i) que[i].scan();
sort(brr + , brr + + m);
m = unique(brr + , brr + + m) - brr - ;
for (int i = ; i <= n; ++i) arr[i] = Get(arr[i]);
for (int i = ; i <= q; ++i) que[i].x = Get(que[i].x);
for (int i = ; i <= n; ++i) segtree.update(segtree.T[arr[i]], , n, p[i], );
for (int i = ; i <= q; ++i)
{
if (que[i].op == )
printf("%d\n", query(que[i].u, que[i].v, que[i].x));
else
{
int u = que[i].u, x = que[i].x;
segtree.update(segtree.T[arr[u]], , n, p[u], -);
arr[u] = x;
segtree.update(segtree.T[arr[u]], , n, p[u], );
}
}
}
} int main()
{
#ifdef LOCAL
freopen("Test.in", "r", stdin);
#endif Run();
return ;
}
5204：水。
#include <bits/stdc++.h>
using namespace std; #define N 100010
int t, n, m, a[N], b[N], cnt[N]; void Hash()
{
for (int i = ; i <= n; ++i) b[i] = a[i];
sort(b + , b + + n);
m = unique(b + , b + + n) - b - ;
for (int i = ; i <= n; ++i) a[i] = lower_bound(b + , b + + m, a[i]) - b;
} bool ok()
{
for (int i = ; i <= m; ++i) if (cnt[i] != cnt[i - ])
return true;
return false;
} void Run()
{
scanf("%d", &t);
while (t--)
{
scanf("%d", &n);
memset(cnt, , sizeof cnt);
for (int i = ; i <= n; ++i) scanf("%d", a + i); Hash();
for (int i = ; i <= n; ++i) ++cnt[a[i]];
if (!ok()) puts("-1");
else
{
int Max = *max_element(cnt + , cnt + + m);
int tot = ;
for (int i = ; i <= m; ++i) if (cnt[i] == Max)
++tot;
printf("%d\n", tot);
for (int i = , j = ; i <= m; ++i) if (cnt[i] == Max)
printf("%d%c", b[i], " \n"[(++j) == tot]);
}
}
} int main()
{
#ifdef LOCAL
freopen("Test.in", "r", stdin);
#endif Run();
return ;
}
5293：lca+前缀点权和
#include <bits/stdc++.h>
using namespace std; #define ll long long
#define N 300010
const ll MOD = (ll);
int n, q;
vector <int> G[N];
int p[N], fp[N], deep[N], fa[N], sze[N], top[N], son[N], cnt;
ll dis[N][]; void DFS(int u)
{
sze[u] = ;
for (int i = , len = G[u].size(); i < len; ++i)
{
int v = G[u][i];
if (v == fa[u]) continue;
fa[v] = u; deep[v] = deep[u] + ;
dis[v][] = deep[v];
dis[v][] = ;
for (int i = ; i <= ; ++i)
dis[v][i] = (dis[v][i - ] * deep[v]) % MOD;
for (int i = ; i <= ; ++i)
dis[v][i] = (dis[v][i] + dis[u][i]) % MOD;
DFS(v); sze[u] += sze[v];
if (son[u] == - || sze[v] > sze[son[u]]) son[u] = v;
}
} void getpos(int u, int sp)
{
top[u] = sp;
p[u] = ++cnt;
fp[cnt] = u;
if (son[u] == -) return;
getpos(son[u], sp);
for (int i = , len = G[u].size(); i < len; ++i)
{
int v = G[u][i];
if (v == fa[u] || v == son[u]) continue;
getpos(v, v);
}
} int querylca(int u, int v)
{
while (top[u] != top[v])
{
if (deep[top[u]] < deep[top[v]])
swap(u, v);
u = fa[top[u]];
}
if (deep[u] > deep[v]) swap(u, v);
return u;
} void Init()
{
for (int i = ; i <= n; ++i) G[i].clear();
memset(son, -, sizeof son);
cnt = ; dis[][] = ;
} void Run()
{
while (scanf("%d", &n) != EOF)
{
Init();
for (int i = , u, v; i < n; ++i)
{
scanf("%d%d", &u, &v);
G[u].push_back(v);
G[v].push_back(u);
}
DFS(); getpos(, );
scanf("%d", &q);
for (int i = , u, v, k; i <= q; ++i)
{
scanf("%d%d%d", &u, &v, &k);
int lca = querylca(u, v);
printf("%lld\n", (dis[u][k] + dis[v][k] - dis[lca][k] - dis[fa[lca]][k] + * MOD) % MOD);
}
}
} int main()
{
#ifdef LOCAL
freopen("Test.in", "r", stdin);
#endif Run();
return ;
}
5301：莫队
#include <bits/stdc++.h>
using namespace std; #define N 100010
#define unit 450
#define ll long long struct qnode
{
int l, r, id;
void scan(int id)
{
scanf("%d%d", &l, &r); --l;
this->id = id;
}
bool operator < (const qnode &r) const
{
int posl = l / unit, posr = r.l / unit;
return posl < posr || posl == posr && this->r < r.r;
}
}que[N];
int n, m, k, a[N], ans[N], cnt[N];
ll res; void add(int x)
{
if (x == -) return;
int pos = a[x] ^ k;
res += cnt[pos];
++cnt[a[x]];
} void del(int x)
{
if (x == -) return;
int pos = a[x] ^ k;
--cnt[a[x]];
res -= cnt[pos];
} void Run()
{
while (scanf("%d%d%d", &n, &m, &k) != EOF)
{
memset(cnt, , sizeof cnt);
for (int i = ; i <= n; ++i) scanf("%d", a + i), a[i] ^= a[i - ];
for (int i = ; i <= m; ++i) que[i].scan(i);
sort(que + , que + + m); cnt[] = ;
for (int i = , l = , r = ; i <= m; ++i)
{
for (; r < que[i].r; ++r) add(r + );
for (; r > que[i].r; --r) del(r);
for (; l < que[i].l; ++l) del(l);
for (; l > que[i].l; --l) add(l - );
ans[que[i].id] = res;
}
for (int i = ; i <= m; ++i) printf("%d\n", ans[i]);
}
} int main()
{
#ifdef LOCAL
freopen("Test.in", "r", stdin);
#endif Run();
return ;
}
5313：循环节
#include <bits/stdc++.h>
using namespace std; int f[]; void Run()
{
f[] = , f[] = ;
for (int i = ; i < ; ++i) f[i] = (f[i - ] + f[i - ]) % ;
int q, x;
while (scanf("%d", &q) != EOF)
{
while (q--)
{
scanf("%d", &x);
printf("%d\n", f[(x - ) % + ]);
}
}
} int main()
{
#ifdef LOCAL
freopen("Test.in", "r", stdin);
#endif Run();
return ;
}
5338：树剖+可持久化Trie
#include <bits/stdc++.h>
using namespace std; #define N 100010
int n, q;
int arr[N];
vector <int> G[N];
int p[N], fp[N], lp[N], rp[N], sze[N], son[N], top[N], deep[N], fa[N], cnt; void DFS(int u)
{
sze[u] = ;
for (int i = , len = G[u].size(); i < len; ++i)
{
int v = G[u][i];
if (v == fa[u]) continue;
fa[v] = u; deep[v] = deep[u] + ;
DFS(v); sze[u] += sze[v];
if (son[u] == - || sze[v] > sze[son[u]]) son[u] = v;
}
} void getpos(int u, int sp)
{
top[u] = sp;
p[u] = ++cnt;
fp[cnt] = u;
lp[u] = cnt;
if (son[u] == -)
{
rp[u] = cnt;
return;
}
getpos(son[u], sp);
for (int i = , len = G[u].size(); i < len; ++i)
{
int v = G[u][i];
if (v == fa[u] || v == son[u]) continue;
getpos(v, v);
}
rp[u] = cnt;
} int T[N];
struct TRIE
{
struct node
{
int son[], cnt;
node() { memset(son, , sizeof son); cnt = ; }
}a[N * ]; int cnt;
void Init()
{
a[] = node();
cnt = ;
}
void Insert(int now, int pre, int val)
{
bitset <> b; b = val;
T[now] = ++cnt;
pre = T[pre];
now = T[now];
a[now] = a[pre];
for (int i = ; i >= ; --i)
{
a[++cnt] = a[a[now].son[b[i]]];
++a[cnt].cnt;
a[now].son[b[i]] = cnt;
now = cnt;
}
}
int query(int lt, int rt, int val)
{
bitset <> b; b = val;
lt = T[lt], rt = T[rt];
int res = ;
for (int i = ; i >= ; --i)
{
int id = b[i] ^ ;
bool flag = true;
if (a[a[rt].son[id]].cnt - a[a[lt].son[id]].cnt <= )
{
id ^= ;
flag = false;
}
if (flag) res += << i;
rt = a[rt].son[id];
lt = a[lt].son[id];
}
return res;
}
}trie; int query(int u, int v, int x)
{
int res = ;
while (top[u] != top[v])
{
if (deep[top[u]] < deep[top[v]])
swap(u, v);
res = max(res, trie.query(p[top[u]] - , p[u], x));
u = fa[top[u]];
}
if (deep[u] > deep[v]) swap(u, v);
res = max(res, trie.query(p[u] - , p[v], x));
return res;
} void Init()
{
memset(son, -, sizeof son);
trie.Init();
} void Run()
{
while (scanf("%d%d", &n, &q) != EOF)
{
Init();
for (int i = ; i <= n; ++i) scanf("%d", arr + i);
for (int i = , u, v; i < n; ++i)
{
scanf("%d%d", &u, &v);
G[u].push_back(v);
G[v].push_back(u);
}
DFS(); getpos(, );
for (int i = ; i <= n; ++i) trie.Insert(i, i - , arr[fp[i]]);
for (int i = , op, x, y, z; i <= q; ++i)
{
scanf("%d%d%d", &op, &x, &y);
if (op == ) printf("%d\n", trie.query(lp[x] - , rp[x], y));
else
{
scanf("%d", &z);
printf("%d\n", query(x, y, z));
}
}
}
} int main()
{
#ifdef LOCAL
freopen("Test.in", "r", stdin);
#endif Run();
return ;
}
end.
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