询问l,r区间的完全平方数的个数

#include <iostream>
#include<bits/stdc++.h>
using namespace std;
long long a[1999999];
int main()
{
    for(long long i=0;i<=999999;i++)
    {
        a[i-1] = i*i;
    }
    int n;
    cin>>n;
    int num = 0;
    for(int i=1;i<=n;i++)
    {
        num = 0;
        long long j = 0;
        long long l,r;
        scanf("%lld%lld",&l,&r);
        int ll = lower_bound(a,a+999999,l)-a;
        int rr = lower_bound(a,a+999999,r)-a;
      // cout<<ll<<" "<<rr<<endl;
       if(a[rr]==r)
        rr++;
        if(l==0)ll--;
       rr--;
       cout<<rr-ll+1<<endl;
    }

    return 0;
}