还有不要在dfs里传vector，肯定炸的TAT

供参考可交流

#define _CRT_SECURE_NO_WARNINGS 1
//#include <bits/stdc++.h>
#include <stdio.h>
#include <iostream>
using namespace std;
#include <unordered_map>
#include <vector>
#include <math.h> 
#include <list> 
#include <map> 
#include <stack>
#include <queue>
#include <set>
#include <unordered_set>
#include <string>
#include <algorithm>//sort
#include <stdlib.h>
#include <iomanip>
#include <cstring>//memset
#include <limits.h>
/*ios::sync_with_stdio(false);
cin.tie(0);*/

int barr[100005] = { 0 };
vector<int>alist[100005];
    int n, m; 
void dfs(int cur)
{
    barr[cur] = 1;
    cout << cur << " ";
    sort(alist[cur].begin(), alist[cur].end());
    for (int x : alist[cur])
    {
        if (barr[x] == 0)
        {
            dfs(x);
        }
    }
}
int main()
{
    //ios::sync_with_stdio(false);
    //cin.tie(0);
    cin >> n >> m;
    for (int i = 0; i < m; i++)
    {
        int x, y; cin >> x >> y;
        alist[x].push_back(y);
    }
    dfs(1);
    cout << endl;
    //bfs
    memset(barr, 0, sizeof barr);
    queue<int>q;
    q.push(1);
    barr[1] = 1;
    while (q.size())
    {
        cout << q.front() << " ";
        for (int x : alist[q.front()])
        {
            if (barr[x] == 0)
            {
                barr[x] = 1;
                q.push(x);
            }
        }
        q.pop();
    }
    return 0;
}