【CF1472G】Moving to the Capital

链接

传送门

code

#include <iostream>
#include <queue>
#include <vector>
#include <cstdio>
#include <algorithm>
#include <cstring>

using namespace std;
const int N = 2e5 + 10;
int n, m;
int dis[N], vis[N], dp[N];
vector<vector<int>> g(N);

void bfs(){
    
    
    queue<int> que;
    dis[1] = 0;
    que.push(1);
    while (que.size()){
    
    
        int u = que.front();
        que.pop();
        for (int v : g[u]) {
    
    
            if (dis[v] == -1){
    
    
                dis[v] = dis[u] + 1;
                que.push(v);
            }
        }
    }
}

void dfs(int u){
    
    
    vis[u] = 1;
    dp[u] = dis[u];
    for (int v : g[u]) {
    
    
        if (!vis[v] && dis[u] < dis[v])
        dfs(v);

        if (dis[v] > dis[u]){
    
    
            dp[u] = min(dp[u], dp[v]);
        }else{
    
    
            dp[u] = min(dp[u], dis[v]);
        }
    }
}

void solve(){
    
    
    for (int i = 0; i <= n; ++i) {
    
    
        g[i].clear();
    }
    g.clear();
    scanf("%d%d", &n, &m);
    for (int i = 0, u, v; i < m; ++i) {
    
    
        scanf("%d%d", &u, &v);
        g[u].push_back(v);
    }
    memset(dis, -1, sizeof dis);
    memset(vis, 0, sizeof vis);
    memset(dp, 0, sizeof dp);
    bfs();
    dfs(1);
    for (int i = 1; i <= n; ++i) {
    
    
        printf("%d ", dp[i]);
    }
    printf("\n");
}

int main(){
    
    
    int cases;
    scanf("%d", &cases);
    while (cases--){
    
    
        solve();
    }
    return 0;
}