计算根号n
#include<bits/stdc++.h>
const double eps = 1e-10;
using namespace std;
double f(double x)
{
return x * x;
}
double n;
double calSqrt(double x)
{
double l = 1, r = 1e10;
while(r - l > eps)
{
double mid = (l + r) / 2;
if(f(mid) <= x) l = mid;
else r = mid;
}
return l;
}
int main()
{
cin >> n;
cout << calSqrt(n);
return 0;
}