当个模板用吧
#include <iostream>
#include <algorithm>
#include <cstdio>
#include <cstring>
#include <cstdlib>
#include <string>
using namespace std;
int main()
{
int n, s[50] = {0};
scanf("%d", &n);
for(int i = 0; i < n; ++i) scanf("%d", &s[i]);
for(int i = 0; i < (1 << n); ++i) {
for(int j = 0; j < n; ++j)
if(i & (1 << j)) printf("%d ", s[j]);
printf("\n");
}
return 0;
}