题解 | #袖珍计算器法#

import java.util.*;


public class Solution {
    /**
     * 
     * @param x int整型 
     * @return int整型
     */
    public int sqrt (int x) {
        // write code here
        if (x == 0) {
            return 0;
        }

        int ans = (int) Math.exp(Math.log(x) * 0.5);

        return (ans + 1) * (ans + 1) <= x ? ans + 1 : ans;
    }
}