(ARRAY)findsquarerootofannumber.cpp

// A C++ program to find floor(sqrt(x) 
#include<bits/stdc++.h> 
using namespace std; 

// Returns floor of square root of x		 
int floorSqrt(int x) 
{	 
	// Base cases 
	if (x == 0 || x == 1) 
	return x; 

	// Do Binary Search for floor(sqrt(x)) 
	int start = 1, end = x, ans=0; 
	while (start <= end) 
	{		 
		int mid = (start + end) / 2; 

		// If x is a perfect square 
	

		// Since we need floor, we update answer when mid*mid is 
		// smaller than x, and move closer to sqrt(x) 
		if (mid*mid <= x) 
		{ 
			start = mid + 1; 
			ans ++; 
		} 
		else // If mid*mid is greater than x 
			end = mid-1;		 
	} 
	return ans; 
} 

// Driver program 
int main() 
{	 
	int x = 3; 
	cout << floorSqrt(x) << endl; 
	return 0; 
}