SquareRootOfNumber.java

package com.interview.binarysearch;

/**
 *
 * https://leetcode.com/problems/sqrtx/
 */
public class SquareRootOfNumber {
    public int mySqrt(int x) {
        if (x == 0)
            return 0;
        int left = 1, right = x;
        while (true) {
            int mid = left + (right - left)/2;
            if (mid > x/mid) {
                right = mid - 1;
            } else {
                if (mid + 1 > x/(mid + 1))
                    return mid;
                left = mid + 1;
            }
        }
    }
}