67 (不是用DFS做的)

#include <bits/stdc++.h>
using namespace std;
#define int long long
int n,m,a[100000];

void Prn(){
    for(int i = 1;i <= m;i++)
        cout << a[i] << " ";
    cout << endl;
}

signed main(){
    ios::sync_with_stdio(false);
    cin.tie(0),cout.tie(0);
    cin >> n >> m;
    for(int i = 1; i <= n; i++){
        a[i] = i;
    }   
    do{
        Prn();
    }while(next_permutation(a + 1, a + n + 1));
    return 0;
}

错在哪？