[leetcode] Sqrt(x)

public class Solution {
    public int sqrt(int x) {
        if (x < 0)
            return -1;
        long right = x / 2 + 1;
        long left = 0;
        long mid;
        while (left <= right) {
            mid = (left + right) / 2;
            if (x < mid * mid)
                right = mid - 1;
            else if (x > mid * mid)
                left = mid + 1;
            else
                return (int) mid;
        }
        return (int) right;

    }

    public static void main(String[] args) {
         System.out.println(new Solution().sqrt(0));
         System.out.println(new Solution().sqrt(1));
         System.out.println(new Solution().sqrt(2));
         System.out.println(new Solution().sqrt(3));
         System.out.println(new Solution().sqrt(4));
        System.out.println(new Solution().sqrt(2147483647));
    }
}