题解 | #求平方根#

import java.util.*;


public class Solution {
    /**
     * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
     *
     *
     * @param x int整型
     * @return int整型
     */
    public int mysqrt (int x) {
        // write code here
        if (x == 0 || x == 1) {
            return x;
        }

        int left = 0;
        int right = x;

        while (left <= right) {
            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;
            }
        }

        return x;
    }
}