Find Square Root of N (Binary Search)

#include<bits/stdc++.h>
#define endl "\n"
using namespace std;

double find_sqrt(int n) {
    double L = 0, R = n;

    while(fabs(L-R) >= 1e-4) {
        double M = (L+R) / 2;
        if(M*M < n) {
            L = M;
        } else {
            R = M;
        }
    }
    return L;
}

int main() {
    int n;
    cin >> n;
    cout << find_sqrt(n) << endl;
    main();


    return 0;
}