#include <iostream>
#include <vector>
#include <queue>
#include <stack>
using namespace std;

vector<int> topologicalSort(int v, vector<vector<int>>& adj) {
    vector<int> inDegree(v + 1, 0);
    vector<int> result;
    queue<int> q;
    
    // 计算入度（考虑重边）
    for (int i = 1; i <= v; ++i) {
        for (int neighbor : adj[i]) {
            inDegree[neighbor]++;
        }
    }
    
    // 初始时按照1~n的顺序将入度为0的点加入队列
    for (int i = 1; i <= v; ++i) {
        if (inDegree[i] == 0) {
            q.push(i);
        }
    }
    
    while (!q.empty()) {
        int u = q.front();
        q.pop();
        result.push_back(u);
        
        for (int neighbor : adj[u]) {
            if (--inDegree[neighbor] == 0) {
                q.push(neighbor);
            }
        }
    }
    
    return result;
}

int main() {
    int v, e;
    cin >> v >> e;
    
    vector<vector<int>> adj(v + 1);
    
    for (int i = 0; i < e; ++i) {
        int a, b;
        cin >> a >> b;
        adj[a].push_back(b);  // 重边会被多次添加，但入度计算会正确处理
    }
    
    vector<int> sorted = topologicalSort(v, adj);
    
    if (sorted.size() != v) {
        cout << "has circle" << endl;
    } else {
        for (int node : sorted) {
            cout << node << " ";
        }
        cout << endl;
    }
    
    return 0;
}

guage #include<bits/stdc++.h> using namespace std; int main(){ long long n; cin>>n; for(int i=1;i<=n;i++){ for(int j=1;j<=n;j++){ for(int m=1;m<=n;m++){ if(i!=j && i!=m && j!=m) cout<<i<<" "<<j<<" "<<m<<endl; }

    }
}
return 0;

}

代一升是我~~爸爸~~儿子


```language
#include<bits/stdc++.h>
using namespace std;
int a[100],v[100],n;
void dfs(int step){
	if(step==n+1){
		for(int i=1;i<=n;i++) cout<<setw(5)<<a[i];
		cout<<endl;
		return ;
	}
	for(int i=1;i<=n;i++){
		if(v[i]==0){
			a[step]=i;
			v[i]=1;
			dfs(step+1);
			v[i]=0;
		}	
	}
}
int main(){
	cin>>n;
	dfs(1);
	return 0;
}