poj 3685 Matrix

#include<cstdio>#include<cstring>#include<iostream>using namespace std;long long n,m;int main(){    int T;    scanf("%d",&T);    while(T--)    {        scanf("%I64d%I64d",&n,&m);        long long l=-100000*n,r=n*n+100000*n+n*n+n*n;        long long ans=0;        while(l<=r)        { long long mid=(l+r)>>1; long long cnt=0; for(long long j=1;j<=n;j++) {     long long sl=1,sr=n;     long long scnt=0;     while(sl<=sr)     {         long long smid=(sl+sr)>>1;         long long val=smid*smid+100000*smid+j*j-100000*j+smid*j;         if(val<=mid)         {  scnt=smid;  sl=smid+1;         }         else  sr=smid-1;     }     cnt+=scnt; } if(cnt>=m) {     ans=mid;     r=mid-1; } else     l=mid+1;        }        printf("%I64dn",ans);    }    return 0;}