1315 合法整数集（位运算+模拟）

#include<bits/stdc++.h>
#include<cstdio>
const int maxn = 55;
const int M = 0x3f3f3f3f;
using namespace std;

int a[maxn];
int vis[maxn];
int dis[maxn];
int logo[maxn];
int k[maxn];
int i,j;
int main()
{
	int n,x;
	while(scanf("%d %d",&n,&x)!=EOF)
	{
		int ans = 0;
		memset(vis, 0, sizeof(vis));
		while(x)
		{
			vis[ans++] = x%2;
			x /= 2;
		}
		memset(logo, 0, sizeof(logo));
		memset(dis, 0, sizeof(dis));
		memset(k, 0, sizeof(k));
		for(i=0; i<n; i++)
		{
			scanf("%d",&a[i]);
			int flag = a[i];
			int d = 0;
			while(flag)
			{
				dis[d++] = flag % 2;
				flag /=2;
				if(dis[d-1] && !vis[d-1])
					logo[i] = 1;
			}
		}
		int num = M;
		for(i=0; i<n; i++)
		{
			if(logo[i])
				continue;
			int flag = a[i];
			int d = 0;
			while(flag)
			{
				k[d++] += flag%2;
				flag /= 2;
			}
		}
		for(i=0; i<ans; i++)
		{
			if(!vis[i])
				continue;
			num = min(k[i],num);
		}
		if(num == M)
			printf("%d\n",0);
		else
			printf("%d\n",num);
	} 
	return 0;	
}