61-binary-sqrt.cpp

#include <iostream>
#include <vector>
using namespace std;

double mySqrt(int x, int prec) {
    int l=0, r=x;
    long long int m= l + (r-l)/2, intAns=m;
    while(l<=r){
        m= l+ (r-l)/2;
        
        if (m*m == x){
          intAns = m;
          break;  
        }
        if(m*m > x){
            r = m-1;
        }
        if(m*m < x){ 
            l = m+1;
            intAns = m;
        }
    }
    double ans = (double)intAns;
    double mul = 1;
    for (int i=0; i< prec; i++){
      cout << "precesion iteration: " << i << endl;
      mul /= 10;
      for (int j=0; j<10; j++){
        double can = ans + mul; 
        cout <<"can: "<<can << " | can*can: " << can*can << endl;
        if (can*can == (double)x){
          return can;
        }
        else if (can*can < (double)x) ans = can;
        else if (can*can > (double)x){
          cout << "breaking the loop \n";
          break;
        }
      }
    }
    return ans;
}

int main() {
  double testD = 1.41421;
  cout << mySqrt(2,10) << endl;
  double bl = testD*testD;
  cout << bl << endl;
  return 0;
}