C++で、引数の指定によってはsqrt（平方根）の値が異なることがある。 ref: http://qiita.com/yuki2006/items/f9de35affb660e64e895

file0.txt

#include <iostream>
#include <cmath>
#include <iomanip>
#include <assert.h>
using namespace std;
int main(){

    long long int calc = sqrt(static_cast<long double>(18014415152484098LL));

    cout << calc <<endl;

    long long int calc2 = sqrt(static_cast<double>(18014415152484098LL));

    cout << calc2 <<endl;

    long long int calc3 = sqrt(static_cast<long long int>(18014415152484098LL));

    cout << calc3 <<endl;

    long long int calc4 = sqrt(18014415152484098LL);

    cout << calc4 <<endl;

    cout<<setprecision(20)<< 18014415152484098LL <<endl;

    cout<<setprecision(20)<< static_cast<double>(18014415152484098LL) <<endl;
    cout<<setprecision(20)<< static_cast<long double>(18014415152484098LL) <<endl;


    return 0;
}

file1.txt

134217789
134217790
134217790
134217790
18014415152484098
18014415152484096
18014415152484098