92. 递归实现指数型枚举

#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
using namespace std;
const int N = 16;int n;
int st[N];void dfs(int u){if(u>n){for(int i=1;i<=n;i++){if(st[i] == 1)printf("%d ",i);}printf("\n");return ;}st[u] = 2;dfs(u+1);st[u] = 0;st[u] = 1;dfs(u+1);st[u] = 0;}
int main(){cin>>n;dfs(1);return 0;
}