LeetCode 492 Construct the Rectangle

题目：

For a web developer, it is very important to know how to design a web page's size. So, given a specific rectangular web page’s area, your job by now is to design a rectangular web page, whose length L and width W satisfy the following requirements:

1. The area of the rectangular web page you designed must equal to the given target area.
2. The width W should not be larger than the length L, which means L >= W.
3. The difference between length L and width W should be as small as possible.

You need to output the length L and the width W of the web page you designed in sequence.

Example:

Input: 4Output: [2, 2]Explanation: The target area is 4, and all the possible ways to construct it are [1,4], [2,2], [4,1]. But according to requirement 2, [1,4] is illegal; according to requirement 3,  [4,1] is not optimal compared to [2,2]. So the length L is 2, and the width W is 2.

Note:

1. The given area won't exceed 10,000,000 and is a positive integer
2. The web page's width and length you designed must be positive integers.

题目链接

题意：

给一个矩形的面积，要求给出符合下列3个条件的长和宽。

1. W 和 L 的乘积必须等于矩形的面积
2. L >= W
3. L-W 的值应尽可能的小

当L == W 且 L * W == area 的时候，最符合情况，这时候L-W最小，所以可以从sqrt（area）开始枚举，把找到第一个可以被area整除的W，这个值就是 L-W 最小的情况。

在写的时候第一次从sqrt（area）枚举L，但是出错，想了想，是sqrt（area）向下取整，导致部分情况 L<W 了。

代码如下：

class Solution {public:    vector<int> constructRectangle(int area) {        vector <int> ans;        for (int w = sqrt(area); w >= 1; w --) {            if (area % w == 0) {                ans.push_back(area/w);                ans.push_back(w);                                return ans;            }        }    }};