Treap初步

模板题

　　bzoj3224: Tyvj 1728 普通平衡树

 #include <bits/stdc++.h>
 #define rep(i, a, b) for (int i = a; i <= b; i++)
 #define REP(i, a, b) for (int i = a; i < b; i++)
 #define drep(i, a, b) for (int i = a; i >= b; i--)
 #define pb push_back
 #define mp make_pair
 #define xx first
 #define yy second
 using namespace std;
 typedef long long i64;
 typedef pair<int, int> pii;
 const int inf = ~0U >> ;
 const i64 INF = ~0ULL >> ;
 //*****************************

 const int maxn = ;
 struct node {
     int l, r, v, w, sz, rnd;
     node () { l = r = v = w = sz = rnd = ; }
 } tr[maxn];
 int ndtot, root, ans;

 int read() {
     int l = , s(); char ch = getchar_unlocked();
     while (ch < '' || ch > '') { if (ch == '-') l = -; ch = getchar_unlocked(); }
     while (ch >= '' && ch <= '') { s = (s << ) + (s << ) + ch - ''; ch = getchar_unlocked(); }
     return l * s;
 }

 void update(int &k) { tr[k].sz = tr[tr[k].l].sz + tr[k].w + tr[tr[k].r].sz; }

 void lturn(int &k) {
     int t = tr[k].r; tr[k].r = tr[t].l; tr[t].l = k;
     tr[t].sz = tr[k].sz; update(k); k = t;
 }

 void rturn(int &k) {
     int t = tr[k].l; tr[k].l = tr[t].r; tr[t].r = k;
     tr[t].sz = tr[k].sz; update(k); k = t;
 }

 void insrt(int &k, int x) {
     if (k == ) {
         k = ++ndtot;
         tr[k].sz = tr[k].w = , tr[k].v = x, tr[k].rnd = rand();
         return;
     }
     tr[k].sz++;
     if (tr[k].v == x) tr[k].w++;
     else if (x > tr[k].v) {
         insrt(tr[k].r, x);
         if (tr[tr[k].r].rnd < tr[k].rnd) lturn(k);
     }
     else {
         insrt(tr[k].l, x);
         if (tr[tr[k].l].rnd < tr[k].rnd) rturn(k);
     }
 }

 void del(int &k, int x) {
     if (k == ) return;
     if (tr[k].v == x) {
         if (tr[k].w > ) {
             tr[k].w--; tr[k].sz--; return;
         }
         if (tr[k].l * tr[k].r == ) k = tr[k].l + tr[k].r;
         else if (tr[tr[k].l].rnd < tr[tr[k].r].rnd) rturn(k), del(k, x);
         else lturn(k), del(k, x);
     }
     else if (x > tr[k].v) tr[k].sz--, del(tr[k].r, x);
     else tr[k].sz--, del(tr[k].l, x);
 }

 int query_rnk(int k, int x) {
     if (k == ) return ;
     if (tr[k].v == x) return tr[tr[k].l].sz + ;
     else if (x > tr[k].v) return tr[tr[k].l].sz + tr[k].w + query_rnk(tr[k].r, x);
     else return query_rnk(tr[k].l, x);
 }

 int query_num(int k, int x) {
     if (k == ) return ;
     if (x <= tr[tr[k].l].sz) return query_num(tr[k].l, x);
     else if (x > tr[tr[k].l].sz + tr[k].w) return query_num(tr[k].r, x - tr[tr[k].l].sz - tr[k].w);
     else return tr[k].v;
 }

 void query_pre(int k, int x) {
     if (k == ) return;
     if (x > tr[k].v) {
         ans = tr[k].v; query_pre(tr[k].r, x);
     }
     else query_pre(tr[k].l, x);
 }

 void query_sub(int k, int x) {
     if (k == ) return;
     if (x < tr[k].v) {
         ans = tr[k].v; query_sub(tr[k].l, x);
     }
     else query_sub(tr[k].r, x);
 }

 int main() {
     int n; n = read();
     while (n--) {
         int op, x; op = read(), x = read();
         switch(op) {
             case : insrt(root, x); break;
             case : del(root, x); break;
             case : printf("%d\n", query_rnk(root, x)); break;
             case : printf("%d\n", query_num(root, x)); break;
             case : ans = ; query_pre(root, x); printf("%d\n", ans); break;
             case : ans = ; query_sub(root, x); printf("%d\n", ans); break;
         }
     }
 }

　　bzoj1503: 郁闷的出纳员

　　　　按理来说Treap保持平衡后是不能旋转的，然而这个题乱搞A了，把要查询的点旋转到根上然后干掉。。

 #include <bits/stdc++.h>
 #define rep(i, a, b) for (int i = a; i <= b; i++)
 #define REP(i, a, b) for (int i = a; i < b; i++)
 #define drep(i, a, b) for (int i = a; i >= b; i--)
 #define mp make_pair
 #define pb push_back
 #define clr(x) memset(x, 0, sizeof(x))
 #define xx first
 #define yy second
 using namespace std;
 typedef long long i64;
 const int inf = ~0U>>;
 const i64 INF = ~0ULL>>;
 //****************************

 const int maxn = ;

 struct node {
     int l, r, v, rnd, w, sz;
     node() { l = r = v = rnd = w = sz = ; }
 } tr[maxn];
 int ndtot, root;
 void update(int k) { tr[k].sz = tr[tr[k].l].sz + tr[k].w + tr[tr[k].r].sz; }
 void lturn(int &k) {
     int t = tr[k].r; tr[k].r = tr[t].l; tr[t].l = k;
     tr[t].sz = tr[k].sz; update(k); k = t;
 }
 void rturn(int &k) {
     int t = tr[k].l; tr[k].l = tr[t].r; tr[t].r = k;
     tr[t].sz = tr[k].sz; update(k); k = t;
 }

 void insrt(int &k, int x) {
     if (!k) {
         k = ++ndtot;
         tr[k].v = x, tr[k].rnd = rand(), tr[k].w = tr[k].sz = ;
         return;
     }
     tr[k].sz++;
     if (tr[k].v == x) tr[k].w++;
     else if (x > tr[k].v) {
         insrt(tr[k].r, x);
         if (tr[tr[k].r].rnd < tr[k].rnd) lturn(k);
     }
     else if (x < tr[k].v) {
         insrt(tr[k].l, x);
         if (tr[tr[k].l].rnd < tr[k].rnd) rturn(k);
     }
 }

 int query_num(int &k, int x) {
     if (!k) return ;
     if (x <= tr[tr[k].l].sz) return query_num(tr[k].l, x);
     else if (x > tr[tr[k].l].sz + tr[k].w) return query_num(tr[k].r, x - tr[tr[k].l].sz - tr[k].w);
     else return tr[k].v;
 }

 void fix(int &k, int x) {
     if (!k) return;
     if (tr[k].v >= x) {
         fix(tr[k].l, x);
         if (tr[k].l && tr[tr[k].l].v >= x) rturn(k);
     }
     else {
         fix(tr[k].r, x);
         if (tr[k].r && tr[tr[k].r].v >= x) lturn(k);
     }
 }

 char str[];
 int main() {
     int n, m;
     scanf("%d%d", &n, &m);
     int tot();
     int be();
     insrt(root, 0x3f3f3f3f);
     while (n--) {
         int x;
         scanf("%s%d", str, &x);
         if (str[] == 'I') { if (x >= m) insrt(root, x - tot), be++; }
         else if (str[] == 'A') tot += x;
         else if (str[] == 'S') {
             tot -= x;
             fix(root, m - tot);
             tr[root].sz -= tr[tr[root].l].sz;
             tr[tr[root].l] = node();
             tr[root].l = ;
         }
         else {
             if (x +  > tr[root].sz) puts("-1");
             else printf("%d\n", query_num(root, tr[root].sz - x) + tot);
         }
     }
     printf("%d\n", be - tr[root].sz + );
     return ;
 }