poj 2590（水题，注意x==y的情况）

#include<iostream>
#include<cmath>
#include<cstdio>
using namespace std;
int main(){
    long long n,x,y,s,n1,ans;
    scanf("%lld",&n);
    while(n--){
        scanf("%lld%lld",&x,&y);
        s = y-x;
        n1 = floor((double)pow((double)s,0.5));
        if(s==0)
            ans = 0;
        else if((n1-1)*n1<s&&s<=n1*n1)
            ans = 2*n1-1;
        else if(n1*n1<s&&s<=n1*(n1+1))
            ans = 2*n1;
        else if(n1*(n1+1)<s&&s<=(n1+1)*(n1+1))
            ans = 2*n1+1;
        printf("%lld\n",ans);
    }
    return 0;
}