2021CCPC网络赛重赛 _ 1011 _ HDU7136 _ Jumping Monkey 并查集，重建树

原题链接

转载博客
写的很好了，这里只做记录:D
贴个代码

#include<bits/stdc++.h>
#define LL long long
#define INF INT64_MAX
#define MOD 998244353
#define ls rt << 1
#define rs rt << 1 | 1
using namespace std;
typedef pair<int,int>pa;
const int N = 1e5+7;
int vis[N], fa[N], d[N];
vector<int> g[N], rg[N];
struct node{
    int id, val;
    bool operator < (const node &x) const{
        return val<x.val;
    }
}a[N];
int Find(int x){
    return x==fa[x]? x : fa[x] = Find(fa[x]);
}
void dfs(int x, int from, int idx){
    d[x] = idx;
    for(auto it:rg[x]){
        if(it==from) continue;
        dfs(it, x, idx+1);
    }
}
int main(){
    int n, m, k, _, u, v;
    scanf("%d", &_);
    while(_--){
        scanf("%d", &n);
        for(int i = 1;i <= n;i++){
            g[i].clear();
            rg[i].clear();
            fa[i] = d[i] = 0;
        }
        for(int i = 1;i <= n-1;i++){
            scanf("%d%d", &u, &v);
            g[u].push_back(v);
            g[v].push_back(u);
        }
        for(int i = 1;i <= n;i++){
            scanf("%d", &a[i].val);
            a[i].id = i;
        }
        sort(a+1, a+1+n);
        for(int i = 1;i <= n;i++){
            fa[a[i].id] = a[i].id;
            for(auto it:g[a[i].id]){
                if(fa[it]){
                    int fx = Find(it);
                    fa[fx] = a[i].id;
                    rg[fx].push_back(a[i].id);
                    rg[a[i].id].push_back(fx);
                }
            }
        }
        dfs(a[n].id, -1, 1);
        for(int i = 1;i <= n;i++){
            printf("%d\n", d[i]);
        }
    }
    return 0;
}