Examp.cpp

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

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


    double start = 1, end = x/2, ans;
    while (start <= end)
    {
        int mid = (start + end) / 2;

        // If x is a perfect square
        if (mid*mid == x)
            return mid;

        // 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 = mid;
        }
        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;
}