遍历子集(内含二进制)

#include<iostream>
using namespace std;

int main()
{
	int n;
	cin >> n;

	for (int i = 0; i < (1 << n); i++)//遍历0~2^n -1
	{
		cout << i << ":";
		for (int j = 0; j < n; j++)
		{
			if (i & (1 << j))//第j位是否为1
			{
				cout << j << " ";
			}
		}
		cout << endl;
	}
	return 0;
}