Easy-23

leetcode   492. Construct the Rectangle           

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.

AC:

/**
 * Return an array of size *returnSize.
 * Note: The returned array must be malloced, assume caller calls free().
 */
int* constructRectangle(int area, int* returnSize) {
    int* result=(int *)malloc(2*sizeof(int));
    int len=sqrt(area);
    for(int i=1;i<=len;i++)
    {
        if(area%i==0)
        {
            result[0]=i;
            result[1]=area/i;
        }
    }
    if(result[0]<result[1])
    {
        len=result[0];
        result[0]=result[1];
        result[1]=len;
    }
    *returnSize=2;
    return result;
}

tip：先开方，找到循环终止点，再一个一个点的找，最后一次符合条件，即为所求。