[BOJ] 15666번 : N과 M (12)

1. problem : 

https://www.acmicpc.net/problem/15666

 

 

2. solution 1 :

#include <bits/stdc++.h>
using namespace std;
int N, M;
int nums[8];
int ans[8]; 

void backTrack(int k) {
	if (k == M) {
		for (int i = 0; i < M; i++) cout << nums[ans[i]] << ' ';
		cout << '\n';
		return;
	}
	int stt = 0;
	if (k != 0) stt = ans[k - 1];
	for (int i = stt; i < N; i++) {
		ans[k] = i;
		backTrack(k + 1);
	}
}

vector<bool> chk(10002);
int main(void) {
	ios::sync_with_stdio(0);
	cin.tie(0);
	cin >> N >> M;
	int idx = 0;
	while (N--) {
		cin >> nums[idx];
		if (chk[nums[idx]]) continue;
		chk[nums[idx]] = true;
		idx++;
	}
	N = idx; 
	sort(nums, nums + N);
	backTrack(0);
}

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