LeetCode 492. Construct the Rectangle

题目描述：

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: 4
Output: [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.

找到最接近的两个因数，使之乘积等于特定值。从给定的area的平方根向两边搜索。

class Solution {
public:
    vector<int> constructRectangle(int area) {
        vector<int> ans(2);
        int t = sqrt(area);
        if (t * t == area) {
            ans[0] = ans[1] = t;
            return ans;
        }
        while (area % t != 0) {
            t--;
        }
        ans[0] = area / t;
        ans[1] = t;
        return ans;
    }
};