全WA求条

#include<bits/stdc++.h>
using namespace std;
int n,a[1005],vis[1005];
void dfs(int step){
    if(step == n){
        for(int i = 1;i <= n;i++){
            cout << "    " << a[i];
        }
        cout << endl;
        return ;
    }
    for(int i = 1;i <= n;i++){
        if(!vis[i]){
            vis[i] = 1;
            a[step] = i;
            dfs(step+1);
            vis[i] = 0;
        }
    }
}
int main(){
    cin >> n;
    dfs(1);
    return 0;
}