[LeetCode By Go 29]492. Construct the Rectangle

马上写了30道题目了，使用golang写起题目来代码简洁明了，还可以非常方便的写测试用例，加上Goland可以进行调试，有如神助。
但无论如何，写了测试就会依赖测试判断对错，用了debug就会依赖debug来寻找出错的地方，这些其实都是自己大脑偷懒把压力推到了测试和工具上，在日常开发上可以这样提高代码质量和工作效率，但是在笔试面试时基本上不会用编译器调试代码，更别说写测试用例了。
因此，之后如果能直接把题目解出来，就不写测试用例了，我也省（写）时（烦）间（啦）嘛。

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: 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.

解题思路

求面积的平方根，然后将根作为宽度w，如果area能整除w，则l=area/w, 否则w减1，再进行相同的判断
注意
有人觉得根可以作为宽度递减判断，也可以作为长度递增判断。但是考虑到求平方根后有可能得到小数，如果将根转换为int后，l < (area/l), 与实际不符，因此平方根应该作为宽度

代码

constructRectangle.go

package _492_Construct_the_Rectangle

import "math"

func constructRectangle(area int) []int {
    var ret []int
    sqrtArea := math.Sqrt(float64(area))
    var w int
    w = int(sqrtArea)

    for ; w > 0; w-- {
        if area % w == 0 {
            l := area / w
            ret = []int{l, w}
            break
        }
    }

    return ret
}