代码

#include <bits/stdc++.h>
#define int long long
using namespace std;

const int N = 1e6 + 5;
int n, m; 

int a, b, in[N];
vector<int>e[N];
queue<int>q;

void bfs(){
	while(!q.empty()){
		int t = q.front();
		q.pop();
		cout << t << " ";
		for(int i = 0; i < e[t].size(); i++){
			int x = e[t][i];
			if(--in[x] == 0){
				q.push(x);
			}
		}
	}
}
//bFS

int l[N], r[N];
bool vis[N];

void dfs(int x){
	cout << x << ' ';
	vis[x] = 1;
	for(int i = 1; i <= m; i++){
		if(l[i] == x){
			if(vis[r[i]] == 0){
				dfs(r[i]);
			}
		}
	}
}
//DFS

signed main(){
	cin >> n >> m;
	for(int i = 1; i <= m; i++){
		cin >> a >> b;
		l[i] = a;
		r[i] = b;
		e[a].push_back(b);
		in[b]++;
	}
	for(int i = 1; i <= n; i++){
		if(in[i] == 0){
			dfs(i);
			q.push(i);
		}
	}
	cout << "\n";
	bfs();
	
	return 0;
}

样例过了， 但WA test 1