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HYSBZ 1036 树的统计Count 树链剖分 线段树

傻缺模板题,练手速和正确率用。。

#include <cstdio>#include <cstring>#include <algorithm>#include <map>#include <set>#include <bitset>#include <queue>#include <stack>#include <string>#include <iostream>#include <cmath>#include <climits>using namespace std;const int maxn = 3e4 + 10;int head[maxn], u[maxn << 1], v[maxn << 1], nxt[maxn << 1], ecnt;int siz[maxn], maxson[maxn], top[maxn], fa[maxn], tid[maxn], idcnt;int n, q, maxv[maxn << 2], sumv[maxn << 2], dep[maxn], sval[maxn], val[maxn];void adde(int uu, int vv) {	u[ecnt] = uu; v[ecnt] = vv;	nxt[ecnt] = head[uu]; head[uu] = ecnt++;}void init() {	memset(head, -1, sizeof(head));	memset(maxson, -1, sizeof(maxson));	idcnt = ecnt = 0;}void dfs1(int now, int nowfa, int nowdep) {	dep[now] = nowdep; fa[now] = nowfa; siz[now] = 1;	for(int i = head[now]; ~i; i = nxt[i]) if(v[i] != nowfa) {		dfs1(v[i], now, nowdep + 1);		siz[now] += siz[v[i]];		if(maxson[now] == -1 || siz[maxson[now]] < siz[v[i]]) {			maxson[now] = v[i];		}	}}void dfs2(int now, int tp) {	tid[now] = ++idcnt;	top[now] = tp;	if(maxson[now] == -1) return;	dfs2(maxson[now], tp);	for(int i = head[now]; ~i; i = nxt[i]) {		if(v[i] != fa[now] && v[i] != maxson[now]) {			dfs2(v[i], v[i]);		}	}}#define lson rt << 1, l, mid#define rson rt << 1 | 1, mid + 1, rvoid pushup(int rt) {	int lc = rt << 1, rc = rt << 1 | 1;	sumv[rt] = sumv[lc] + sumv[rc];	maxv[rt] = max(maxv[lc], maxv[rc]);}void build(int rt, int l, int r) {	int mid = (l + r) >> 1;	if(l == r) sumv[rt] = maxv[rt] = sval[l];	else {		build(lson); build(rson);		pushup(rt);	}}void update(int rt, int l, int r, int pos, int Val) {	if(l == r) maxv[rt] = sumv[rt] = Val;	else {		int mid = (l + r) >> 1;		if(pos <= mid) update(lson, pos, Val);		else update(rson, pos, Val);		pushup(rt);	}}int query_max(int rt, int l, int r, int ql, int qr) {	if(ql <= l && qr >= r) return maxv[rt];	int mid = l + r >> 1, ret = -1e9;	if(ql <= mid) ret = max(ret, query_max(lson, ql, qr));	if(qr > mid) ret = max(ret, query_max(rson, ql, qr));	return ret;}int query_sum(int rt, int l, int r, int ql, int qr) {	if(ql <= l && qr >= r) return sumv[rt];	int mid = l + r >> 1, ret = 0;	if(ql <= mid) ret += query_sum(lson, ql, qr);	if(qr > mid) ret += query_sum(rson, ql, qr);	return ret;}int ask_max(int x, int y) {	int ret = -1e9;	while(top[x] != top[y]) {		if(dep[top[x]] < dep[top[y]]) {			swap(x, y);		}		ret = max(ret, query_max(1, 1, idcnt, tid[top[x]], tid[x]));		x = fa[top[x]];	}	if(dep[x] > dep[y]) swap(x, y);	ret = max(ret, query_max(1, 1, idcnt, tid[x], tid[y]));	return ret;}int ask_sum(int x, int y) {	int ret = 0;	while(top[x] != top[y]) {		if(dep[top[x]] < dep[top[y]]) swap(x, y);		ret += query_sum(1, 1, idcnt, tid[top[x]], tid[x]);		x = fa[top[x]];	}	if(dep[x] > dep[y]) swap(x, y);	ret += query_sum(1, 1, idcnt, tid[x], tid[y]);	return ret;}int main() {	while(scanf("%d", &n) != EOF) {		init();		for(int i = 1; i < n; i++) {			int a, b; scanf("%d%d", &a, &b);			adde(a, b); adde(b, a);		}		for(int i = 1; i <= n; i++) scanf("%d", &val[i]);		scanf("%d", &q);		dfs1(1, 1, 1); 		dfs2(1, 1);		for(int i = 1; i <= n; i++) {			sval[tid[i]] = val[i];		}		build(1, 1, idcnt);		char cmd[16];		int a, b, c;		while(q--) {			scanf("%s%d%d", cmd, &a, &b);			if(strcmp("QMAX", cmd) == 0) {				printf("%d\n", ask_max(a, b));			}			else if(strcmp("QSUM", cmd) == 0) {				printf("%d\n", ask_sum(a, b));			}			else {				update(1, 1, idcnt, tid[a], b);			}		}	}	return 0;}

  

HYSBZ 1036 树的统计Count 树链剖分 线段树