题解 | #求平方根#二分法，注意用/不用* 避免越界

import java.util.*;


public class Solution {
    /**
     * 
     * @param x int整型 
     * @return int整型
     */
    public int mysqrt (int x) {
        // write code here
        if(x <= 0){
            return 0;
        }
        int left = 0;
        int right = x;
        while(left < right){
            int m = left + (right + 1 - left) / 2;
            if(x / m >= m && x / (m + 1) < (m + 1)){
                return m;
            } else {
                if(x / m >= m){
                    left = m + 1;
                } else {
                    right = m -1;
                }
            }
        }
        return left;
    }
}