杭电1995

//找规律即可，下附打表
#include<stdio.h>
int main()
{
    int n;
    scanf("%d",&n);
    while(n--)
    {
        int a,b;
        scanf("%d%d",&a,&b);
        printf("%lld
",(long long)1<<(a-b));
    }
}

//打表法
#include<stdio.h>
long long a[60];

void cus(int x,long long y)
{
    if(x>=60)
        return ;
    a[x]=y;
    cus(x+1,y*2);
}

int main()
{
    cus(0,1);
    int n;
    scanf("%d",&n);
    while(n--)
    {
        int b,c;
        scanf("%d%d",&b,&c);
        printf("%lld
",a[b-c]);
    }
}