💻 C++ 기반

N과 M (2)
https://www.acmicpc.net/problem/15650

1. 백트래킹 코드

#include <cstdio>

#define MAX 9

using namespace std;

int N, M;
int arr[MAX];
bool isUsed[MAX];

void func(int K)
{
    if (K == M)
    {
        for (int i = 0; i < M; i++)
        {
            printf("%d ", arr[i]);
        }
        printf("\n");
        return;
    }
    for (int i = 1; i <= N; i++)
    {
        if (!isUsed[i])
        {
            if (K == 0 || K != 0 && arr[K - 1] < i)
            {
                isUsed[i] = true;
                arr[K] = i;
                func(K + 1);
                isUsed[i] = false;
            }
        }
    }
}

int main()
{
    scanf("%d %d", &N, &M);
    func(0);
    return 0;
}

2. next_permutation 코드

#include <cstdio>
#include <algorithm>

#define MAX 9

using namespace std;

int N, M;
int arr[MAX];

int main()
{
    scanf("%d %d", &N, &M);
    for (int i = 0; i < M; i++)
    {
        arr[i] = 0;
    }
    for (int i = M; i < N; i++)
    {
        arr[i] = 1;
    }

    do
    {
        for (int i = 0; i < N; i++)
        {
            if (!arr[i])
            {
                printf("%d ", i + 1);
            }
        }
        printf("\n");
    } while (next_permutation(arr, arr + N));
    
    return 0;
}