一般组合

#include<cstdio>
#include<cstring>
using namespace std;
const int maxn = 100;

int n,m;
int rcd[maxn],num[maxn],vis[maxn];

int read_input(){

   if(scanf("%d %d",&n,&m)==EOF)
        return 0;
    for(int i=0;i<n;i++)
        scanf("%d",&num[i]);
    return 1;
}

void select_combination(int l,int p){
    if(l==m){
        for(int i=0;i<m;i++){
            printf("%d",rcd[i]);
        if(i<m-1)
            printf(" ");
        }
        printf("\n");
        return ;
    }
    for(int i=p;i<n;i++){
        rcd[l]=num[i];
        select_combination(l+1,i+1);

    }
}
int main() {
    while(read_input()){

        select_combination(0,0);

    }

    return 0;
}