LCA模板

/*  gyt
       Live up to every day            */
#pragma comment(linker,"/STACK:1024000000,1024000000")
#include<cstdio>
#include<cmath>
#include<iostream>
#include<algorithm>
#include<vector>
#include<stack>
#include<cstring>
#include<queue>
#include<set>
#include<string>
#include<map>
#include <time.h>
#define PI acos(-1)
using namespace std;
typedef long long ll;
typedef double db;
const int maxn = 1e5+5;
const ll maxm = 1e7;
const ll base = 2333;
const int INF = 1<<30;
const db eps = 1e-8;
const ll mod = 1e9+7;
struct Edge{
    int u, v, next, val;
}edge[maxn*2], edge1[maxn*2];
int n, m;
int head[maxn], head1[maxn];
int father[maxn], dis[maxn], tol, toll, LCA[maxn];
bool visit[maxn];
int cnt;
//LCA[]最近公共祖先

void init() {
    cnt=0;
    memset(head, -1, sizeof(head));
    memset(head1, -1, sizeof(head1));
    tol=toll=0;
    memset(visit, 0, sizeof(visit));
    memset(LCA, 0, sizeof(LCA));
    memset(dis, 0, sizeof(dis));
}
void add(int u, int v, int w) {
    edge[tol].u=u, edge[tol].v=v,edge[tol].val=w;
    edge[tol].next=head[u];
    head[u]=tol++;
}
void add1(int u, int v, int w) {
    edge1[toll].u=u, edge1[toll].v=v,edge1[toll].val=w;
    edge1[toll].next=head1[u];
    head1[u]=toll++;
}
int Find(int x) {
    if (x!=father[x])  father[x]=Find(father[x]);
    return father[x];
}
void tarjan(int u) {
    visit[u]=1;
    father[u]=u;
    for (int j=head1[u]; ~j; j=edge1[j].next) {
        int v=edge1[j].v;
        if (visit[v])  LCA[edge1[j].val]=Find(v);
    }
    for (int j=head[u]; ~j; j=edge[j].next) {
        int v=edge[j].v;
        if (!visit[v]) {
            dis[v]=dis[u]+edge[j].val;
            tarjan(v);
            father[v]=u;
            //cout<<dis[v]<<endl;
        }
    }
}
void solve() {
    init();
    scanf("%d%d", &n, &m);
    for (int i=1; i<n; i++) {
        int a, b, c;  scanf("%d%d%d", &a, &b, &c);
        add(a, b, c);  add(b, a, c);
    }
    for (int i=0; i<m; i++) {
        int a, b;  scanf("%d%d", &a, &b);
        add1(a, b, i);  add1(b, a, i);
    }
    dis[1]=0;
    tarjan(1);
    for(int i=0;i<toll;i+=2){
        printf("%d\n",LCA[edge1[i].val]);
    }
}
int main() {
    int t = 1;
    //freopen("in.txt","r",stdin);
  //  freopen("gcd.out","w",stdout);
     scanf("%d", &t);
    while(t--)
        solve();
    return 0;
}