ACdream 1061:郭氏树

把A当作原点就可以了

#include<iostream>#include<cstdio>#include<cmath>using namespace std;typedef long long LL;int main(){    LL x,y;    int t;    scanf("%d",&t);    unsigned long long z;    while(t--)    {        scanf("%lld%lld",&x,&y);        if(y>x) z=y-x;        else z=x-y;        printf("%llu\n",z);    }    return 0;}