BOJ15650: N과 M (2)

#include <bits/stdc++.h>
using namespace std;
int n, m;
vector<int> a;
int main(void) {
    ios::sync_with_stdio(0);
    cin.tie(0);
    cin >> n >> m;
    
    for (int i = 0; i < m; i++) a.push_back(0);
    for (int i = 0; i < n - m; i++) a.push_back(1);
    do {
        for (int i = 0; i < n; i++) {
            if (a[i] == 0) cout << i + 1 << ' ';
        }
        cout << '\n';
    } while (next_permutation(a.begin(), a.end()));
}