Description:
Implement int sqrt(int x)
.
Compute and return the square root of x, where x is guaranteed to be a non-negative integer.
Since the return type is an integer, the decimal digits are truncated and only the integer part of the result is returned.
Example 1:
Input: 4 Output: 2
Example 2:
Input: 8 Output: 2 Explanation: The square root of 8 is 2.82842..., and since the decimal part is truncated, 2 is returned.
Solution:
Code:
public int mySqrt(int x) { int left = 0, right = x; if (x <= 1){ return x; } while (left < right){ int mid = left + (right - left)/2; // mid写左半以免越界! if (x / mid >= mid){ // 如果x大于mid^2,证明mid太小,要取右半 left = mid + 1; // 如果x刚好等于^2,也将其+1,便于之后取-1的结果 }else{ right = mid; // 如果x小于mid^2,证明mid太大,要取左半 } } return right-1; }
提交情况:
Runtime: 1 ms, faster than 100.00% of Java online submissions for Sqrt(x).
Memory Usage: 32.3 MB, less than 100.00% of Java online submissions for Sqrt(x).
原文地址:https://www.cnblogs.com/zingg7/p/10679062.html
时间: 2024-10-09 11:34:22