my code:

// 1705.cpp : Defines the entry point for the console application.
//

#include <iostream>
using namespace std;
double sqroot(double);
int main()
{
    int t;
    cin>>t;
    long long int input[50001];
    long long int output[50001];
    for(int i=0;i<t;i++)
    {
        scanf("%lli",&input[i]);
        long long int k=2;
        k=sqroot((double)input[i]);
        if(k<1) k = 1;
        while(true )
        {
            if(input[i]/k==(input[i]/(k+1)))
                break;
            else
                k++;
        }
        output[i]=k;
    }
    for(int i=0;i<t;i++)
        printf("%lli\n",output[i]);
    return 0;
}

inline double sqroot(double n)
{
    double begin=0;
    double end=n;
    double res=0;
    double precision=0.1;
    while(end-begin>precision)
    {
        res=(begin+end)/2;
        if(res*res>n)
            end=res;
        else
            begin=res;
    }
    return res;
}
for n=10^18 loop execute about 30000 times
May this be the couse of time limit??