LeetCode 69 Sqrt(x)（Math、Binary Search）（*）

翻译

[code]实现int sqrt(int x)。

计算并返回x的平方根。

原文

[code]Implement int sqrt(int x).

Compute and return the square root of x.

分析

代码

[code]class Solution {
public:
    int mySqrtHelper(int x, int left, int right) {
        if (x == 0) return 0;
        if (x == 1) return 1;
        int mid = left + (right - left) / 2;
        if (mid > x / mid) right = mid;
        if (mid <= x / mid)left = mid;
        if (right - left <= 1) return left;
        else mySqrtHelper(x, left, right);
    }

    int mySqrt(int x) {
        return mySqrtHelper(x, 0, x);
    }
};