一、题目内容

二、题解

解法1：

思路

时间复杂度 O(logx)O(logx)，用二分法

代码

public class Solution {
    public int sqrt (int x) {
        // write code here
        long left = 1,right = x,mid = (left+right)/2;
        while(left!=mid){
            long temp = mid * mid;
            if(temp == x){
                break;
            }else if(temp>x){
                right = mid;
            }else{
                left = mid;
            }
            mid = (left+right)/2;
        }
        return (int)mid;
    }
}