【BZOJ 3052】【WC 2013】糖果公园

对树的dfs序分块，打开了新世界的大门233

第一关键字是l所在的块，第二关键字是r所在的块，第三关键字是时间，分完块后暴力莫队即可

#include<cmath>
#include<cstdio>
#include<cstring>
#include<algorithm>
using namespace std;
typedef long long ll;
const int N = 100003;
void read(int &k) {
	k = 0; int fh = 1; char c = getchar();
	for(; c < '0' || c > '9'; c = getchar())
		if (c == '-') fh = -1;
	for(; c >= '0' && c <= '9'; c = getchar())
		k = (k << 1) + (k << 3) + c - '0';
	k = k * fh;
}

bool vis[N];
ll A[N], ans = 0;
struct TIME {int x, y, la;} Time[N];
struct edge {int nxt, to;} E[N << 1];
struct node {int l, r, lca, id, tim;} Q[N];
int cal[N], n, m, q, V[N], W[N], f[N][17], deep[N], bel[N << 1];
int point[N], color[N], colorchange[N], pos[N << 1], L[N], R[N], cnt = 0;

void ins(int x, int y) {E[++cnt].nxt = point[x]; E[cnt].to = y; point[x] = cnt;}
void _(int x, int fa) {
	pos[L[x] = ++cnt] = x;
	for(int i = 1; i <= 16; ++i) {f[x][i] = f[f[x][i - 1]][i - 1]; if (f[x][i] == 0) break;}
	for(int tmp = point[x]; tmp; tmp = E[tmp].nxt)
		if (E[tmp].to != fa)
			{deep[E[tmp].to] = deep[x] + 1; f[E[tmp].to][0] = x; _(E[tmp].to, x);}
	pos[R[x] = ++cnt] = x;
}
int LCA(int x, int y) {
	if (deep[x] < deep[y]) swap(x, y);
	int d = deep[x] - deep[y];
	for(int i = 0; i <= 16; ++i) if (d & (1 << i)) x = f[x][i];
	if (x == y) return x;
	for(int i = 16; i >= 0; --i) if (f[x][i] != f[y][i]) x = f[x][i], y = f[y][i];
	return f[x][0];
}
void update(int x) {
	if (vis[x]) {ans -= 1ll * V[color[x]] * W[cal[color[x]]]; --cal[color[x]];}
	else {++cal[color[x]]; ans += 1ll * V[color[x]] * W[cal[color[x]]];}
	vis[x] = !vis[x];
}
void change(int a, int b) {
	if (vis[a]) {update(a); color[a] = b; update(a);}
	else color[a] = b;
}
void Timechange(int &a, int b) {
	while (a < b) {++a; change(Time[a].x, Time[a].y);}
	while (a > b) {change(Time[a].x, Time[a].la); --a;}
}
bool cmp(node A, node B) {return bel[A.l] == bel[B.l] ? (bel[A.r] == bel[B.r] ? A.tim < B.tim : A.r < B.r) : A.l < B.l;}

int main() {
	read(n); read(m); read(q);
	for(int i = 1; i <= m; ++i) read(V[i]);
	for(int i = 1; i <= n; ++i) read(W[i]);
	int op, u, v, timecount = 0, tmp = 0, lca;
	for(int i = 1; i < n; ++i) {
		read(u); read(v);
		ins(u, v); ins(v, u);
	}
	for(int i = 1; i <= n; ++i) read(color[i]), colorchange[i] = color[i];

	cnt = 0;
	_(1, 0);

	for(int i = 1; i <= q; ++i) {
		read(op); read(u); read(v);
		if (op == 0) {Time[++timecount] = (TIME) {u, v, colorchange[u]}; colorchange[u] = v;}
		else {
			if (L[u] > L[v]) swap(u, v);
			lca = LCA(u, v);
			if (lca == u) Q[++tmp] = (node) {L[u], L[v], 0, tmp, timecount};
			else Q[++tmp] = (node) {R[u], L[v], lca, tmp, timecount};
		}
	}

	int nn = n << 1, sq = pow(nn, 2.0 / 3) * 0.5, sign = 0; cnt = 1;
	for(int i = 1; i <= nn; ++i) {
		bel[i] = sign;
		++cnt; if (cnt > sq) {cnt = 1; ++sign;}
	}

	sort(Q + 1, Q + tmp + 1, cmp);

	int l = 1, r = 0, now = 0, tol, tor;
	for(int i = 1; i <= tmp; ++i) {
		tol = Q[i].l; tor = Q[i].r;
		Timechange(now, Q[i].tim);
		while (l < tol) update(pos[l++]);
		while (l > tol) update(pos[--l]);
		while (r < tor) update(pos[++r]);
		while (r > tor) update(pos[r--]);
		if (Q[i].lca) update(Q[i].lca);
		A[Q[i].id] = ans;
		if (Q[i].lca) update(Q[i].lca);
	}

	for(int i = 1; i <= tmp; ++i) printf("%lld\n", A[i]);

	return 0;
}

dfs序分块战术核导弹速度超快～