BZOJ 3531: [Sdoi2014]旅行 (树剖+动态开点线段树)

对于每种信仰维护一棵动态开点线段树就行了…

#include <cstdio>
#include <cctype>
#include <cstring>
#include <algorithm>
using namespace std;
typedef long long LL;
inline void read(int &num) {
	char ch; int flg=1; while(!isdigit(ch=getchar()))if(ch=='-')flg=-flg;
	for(num=0; isdigit(ch); num=num*10+ch-'0',ch=getchar()); num*=flg;
}
const int MAXN = 100005;
const int INF = 1e9;

int n, m, cnt, tmr, fir[MAXN], fa[MAXN], dfn[MAXN], top[MAXN], sz[MAXN], son[MAXN], dep[MAXN];
struct edge { int to, nxt; }e[MAXN<<1];
inline void Add(int u, int v) {
	e[cnt] = (edge){ v, fir[u] }, fir[u] = cnt++;
}
void dfs(int x) {
	dep[x] = dep[fa[x]] + (sz[x]=1);
	for(int v, i = fir[x]; ~i; i = e[i].nxt) 
		if((v=e[i].to) != fa[x]) {
			fa[v] = x, dfs(v), sz[x] += sz[v];
			if(sz[v] > sz[son[x]]) son[x] = v;
		}
}
void dfs2(int x, int tp) {
	top[x] = tp; dfn[x] = ++tmr;
	if(son[x]) dfs2(son[x], tp);
	for(int v, i = fir[x]; ~i; i = e[i].nxt)
		if((v=e[i].to) != son[x] && v != fa[x]) dfs2(v, v);
}

namespace SegmentTree {
	struct seg {
		seg *ls, *rs;
		int mx, sum;
		inline void* operator new(size_t, seg *_ls, seg *_rs, int _mx, int _sum) {
			static seg *mempool, *C;
			if(mempool == C) mempool = (C = new seg[1<<15]) + (1<<15);
			C->ls = _ls;
			C->rs = _rs;
			C->mx = _mx;
			C->sum = _sum;
			return C++;
		}
	}*rt[MAXN];
	inline void update(seg *x) {
		x->mx = x->sum = 0;
		if(x->ls) x->mx = max(x->mx, x->ls->mx), x->sum += x->ls->sum;
		if(x->rs) x->mx = max(x->mx, x->rs->mx), x->sum += x->rs->sum;
	}
	void insert(seg *&x, int l, int r, int pos, int val) {
		if(!x) x = new(0x0, 0x0, 0, 0) seg;
		if(l == r) {
			x->sum = x->mx = val;
			return;
		}
		int mid = (l + r) >> 1;
		if(pos <= mid) insert(x->ls, l, mid, pos, val);
		else insert(x->rs, mid+1, r, pos, val);
		update(x);
	}
	int querysum(seg *p, int l, int r, int x, int y) {
		if(!p) return 0;
		if(l == x && r == y) return p->sum;
		int mid = (l + r) >> 1;
		if(y <= mid) return querysum(p->ls, l, mid, x, y);
		else if(x > mid) return querysum(p->rs, mid+1, r, x, y);
		else return querysum(p->ls, l, mid, x, mid) + querysum(p->rs, mid+1, r, mid+1, y);
	}
	int querymx(seg *p, int l, int r, int x, int y) {
		if(!p) return 0;
		if(l == x && r == y) return p->mx;
		int mid = (l + r) >> 1;
		if(y <= mid) return querymx(p->ls, l, mid, x, y);
		else if(x > mid) return querymx(p->rs, mid+1, r, x, y);
		else return max(querymx(p->ls, l, mid, x, mid), querymx(p->rs, mid+1, r, mid+1, y));
	}
}
inline int Sum(SegmentTree::seg *r, int x, int y) {
	int res = 0;
	while(top[x] != top[y]) {
		if(dep[top[x]] < dep[top[y]]) swap(x, y);
		res += SegmentTree::querysum(r, 1, n, dfn[top[x]], dfn[x]);
		x = fa[top[x]];
	}
	if(dep[x] < dep[y]) swap(x, y);
	res += SegmentTree::querysum(r, 1, n, dfn[y], dfn[x]);
	return res;
}
inline int Max(SegmentTree::seg *r, int x, int y) {
	int res = 0;
	while(top[x] != top[y]) {
		if(dep[top[x]] < dep[top[y]]) swap(x, y);
		res = max(res, SegmentTree::querymx(r, 1, n, dfn[top[x]], dfn[x]));
		x = fa[top[x]];
	}
	if(dep[x] < dep[y]) swap(x, y);
	res = max(res, SegmentTree::querymx(r, 1, n, dfn[y], dfn[x]));
	return res;
}
int c[MAXN], w[MAXN];
int main() {
	memset(fir, -1, sizeof fir);
	read(n), read(m);
	for(int i = 1; i <= n; ++i) read(w[i]), read(c[i]);
	for(int x, y, i = 1; i < n; ++i) {
		read(x), read(y);
		Add(x, y), Add(y, x);
	}
	dfs(1); dfs2(1, 1);
	for(int i = 1; i <= n; ++i) SegmentTree::insert(SegmentTree::rt[c[i]], 1, n, dfn[i], w[i]);
	int x, y; char s[2];
	while(m--) {
		while(!isalpha(s[0] = getchar())); s[1] = getchar();
		read(x), read(y);
		if(s[0] == 'C' && s[1] == 'W') SegmentTree::insert(SegmentTree::rt[c[x]], 1, n, dfn[x], w[x]=y);
		else if(s[0] == 'C' && s[1] == 'C') SegmentTree::insert(SegmentTree::rt[c[x]], 1, n, dfn[x], 0), c[x] = y, SegmentTree::insert(SegmentTree::rt[c[x]], 1, n, dfn[x], w[x]);
		else if(s[0] == 'Q' && s[1] == 'S') printf("%d\n", Sum(SegmentTree::rt[c[x]], x, y));
		else printf("%d\n", Max(SegmentTree::rt[c[x]], x, y));
	}
}