10718 - Bit Mask

描述：题意很简单，可是如果要从L到U之间用 | 遍历的话会超时，只能换种思路了
#include <cstdio>
#include <cstdlib>
int main()
{
 //   freopen("a.txt","r",stdin);
    int n,l,u;
    unsigned int m;
    while(scanf("%d%d%d",&n,&l,&u)!=EOF)
    {
        m=0;
        for(int i=31; i>=0; i--)
            if(m+ (1<<i) <=u&&( (n& (1<<i) ) ==0||( m<l&& (l& (1<<i) )  ) ) ) m+=(1<<i);
        printf("%u\n",m);
    }
    return 0;
}