hdoj--5100--Chessboard（数学推理）



Chessboard

Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)
Total Submission(s): 910    Accepted Submission(s): 384

Problem Description

Consider the problem of tiling an n×n chessboard by polyomino pieces that are k×1 in size; Every one of the k pieces of each polyomino tile must align exactly with one of the chessboard squares. Your task is to figure out the maximum number of chessboard squares tiled.

 

Input

There are multiple test cases in the input file.
First line contain the number of cases T (T≤10000).
In the next T lines contain T cases , Each case has two integers n and k. (1≤n,k≤100)

 

Output

Print the maximum number of chessboard squares tiled.

 

Sample Input

2
6 3
5 3

 

Sample Output

36
24

 

Source

BestCoder Round #17

我去你妹的数学题，真坑

http://www.matrix67.com/blog/archives/5900

#include<cstdio>
#include<cstring>
int main()
{
	int t;
	scanf("%d",&t);
	while(t--)
	{
		int n,k;
		scanf("%d%d",&n,&k);
		if(k>n)
			printf("0
");
		else
		{
			int num=n%k;
			if(num>k/2)
			num-=k;
			printf("%d
",n*n-num*num);
		}
	}
	return 0;
}