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 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; } }