不胜感激

#include <bits/stdc++.h>
using namespace std;
const int N = 1e5 + 9, LOGN = 22;
struct Edge{
	int v, nex;
} e[N << 1];
int head[N], ecnt;
void addEdge(int u, int v){
	e[++ecnt] = Edge{v, head[u]};
	head[u] = ecnt;
}
struct Node{
	int ls, rs, sum, res;
} t[50 * N];
int ans[N], cnt;
//线段树pushup 
void update(int x){
	if(t[t[x].ls].sum < t[t[x].rs].sum) {
    	t[x].res = t[t[x].rs].res;
    	t[x].sum = t[t[x].rs].sum;
  	} else {
    	t[x].res = t[t[x].ls].res;
    	t[x].sum = t[t[x].ls].sum;
  	}
}
//线段树合并 
int modify(int a, int b, int l, int r) {
  	if(!a) 
	  return b;
  	if(!b) 
	  return a;
  	if(l == r) {
    	t[a].sum += t[b].sum;
    	return a;
  	}
  	int mid = (l + r) >> 1;
  	t[a].ls = modify(t[a].ls, t[b].ls, l, mid);
  	t[a].rs = modify(t[a].rs, t[b].rs, mid + 1, r);
  	update(a);
  	return a;
}
//动态开点线段树 
int Build(int id, int l, int r, int co, int z) {
  	if(!id)
	  	id = ++cnt;
  	if(l == r) {
		t[id].sum += z;
    	t[id].res = co;
    	return id;
  	}
  	int mid = (l + r) >> 1;
  	if(co <= mid)
    	t[id].ls = Build(t[id].ls, l, mid, co, z);
  	else
    	t[id].rs = Build(t[id].rs, mid + 1, r, co, z);
  	update(id);
  	return id;
}
int fa[N][LOGN], dep[N], rt[N];
//求每个节点的深度和父亲 
void dfs1(int u, int fat){
	for(int i = head[u]; i; i = e[i].nex){
		int v = e[i].v;
		if(v != fat){
			fa[v][0] = u;
			dep[v] = dep[u] + 1;
			dfs1(v, u);
		}
	}
}
//求最近公共祖先 
int query(int x, int y){
	if(dep[x] > dep[y])
		swap(x, y);
	int d = dep[y] - dep[x];
	int t = 0;
	while(d){
		if(d & 1)
			y = fa[y][t];
		++t;
		d >>= 1;
	}
	t = 0;
	while(fa[x][t] != fa[y][t])
		++t;
	--t;
	while(t >= 0){
		if(fa[x][t] != fa[y][t]){
			x = fa[x][t];
			y = fa[y][t];
		}
		--t;
	}
	if(x != y){
		x = fa[x][0];
		y = fa[y][0];
	}
	return x;
}
//树上前缀和 
void dfs2(int u) {
  	for(int i = head[u]; i; i = e[i].nex) {
  		int v = e[i].v;
    	if(v == fa[u][0])
			continue;
    	dfs2(v);
    	rt[u] = modify(rt[u], rt[v], 1, 100000);
  	}
  	ans[u] = t[rt[u]].res;
  	if(t[rt[u]].sum == 0)
	  	ans[u] = 0;
}
int n, m;
int main(){
	scanf("%d%d", &n, &m);
	for(int i = 1; i < n; i++){
		int u, v;
		scanf("%d%d", &u, &v);
		addEdge(u, v);
		addEdge(v, u);
	}
	fa[1][0] = 1;
	dfs1(1, 1);
	for(int j = 1, j2 = 2; j2 <= n; ++j, j2 <<= 1)
		for(int i = 1; i <= n; ++i)
			fa[i][j] = fa[fa[i][j - 1]][j - 1];
	for(int i = 1; i <= m; i++){
		int x, y, z;
		scanf("%d%d%d", &x, &y, &z);
		int lca = query(x, y);
		//树上差分 
		rt[x] = Build(rt[x], 1, 100000, z, 1);
		rt[y] = Build(rt[y], 1, 100000, z, 1);
		rt[lca] = Build(rt[lca], 1, 100000, z, -1);
		rt[fa[lca][0]] = Build(rt[fa[lca][0]], 1, 100000, z, -1);
	}
	dfs2(1);
	for(int i = 1; i <= n; i++)
		printf("%d\n", ans[i]);
	return 0;
}