#### Square Root Binary Search

s
```package com.thealgorithms.searches;

import java.util.Scanner;

/**
* Given an integer x, find the square root of x. If x is not a perfect square,
* then return floor(√x).
* <p>
* For example, if x = 5, The answer should be 2 which is the floor value of √5.
* <p>
* The approach that will be used for solving the above problem is not going to
* be a straight forward Math.sqrt(). Instead we will be using Binary Search to
* find the square root of a number in the most optimised way.
*
* @author sahil
*/
public class SquareRootBinarySearch {

/**
* This is the driver method.
*
* @param args Command line arguments
*/
public static void main(String args[]) {
Scanner sc = new Scanner(System.in);
System.out.print("Enter a number you want to calculate square root of : ");
int num = sc.nextInt();
long ans = squareRoot(num);
System.out.println("The square root is : " + ans);
}

/**
* This function calculates the floor of square root of a number. We use
* Binary Search algorithm to calculate the square root in a more optimised
* way.
*
* @param num Number
*/
private static long squareRoot(long num) {
if (num == 0 || num == 1) {
return num;
}
long l = 1;
long r = num;
long ans = 0;
while (l <= r) {
long mid = l + (r - l) / 2;
if (mid == num / mid) {
return mid;
} else if (mid < num / mid) {
ans = mid;
l = mid + 1;
} else {
r = mid - 1;
}
}
return ans;
}
}
```  