Triangular Sums

Triangular Sums

时间限制：3000 ms  |  内存限制：65535 KB

难度：2

 

描述

The n^th Triangular number, T(n) = 1 + … + n, is the sum of the first n integers. It is the number of points in a triangular array with n points on side. For example T(4):

X
X X
X X X
X X X X

Write a program to compute the weighted sum of triangular numbers:

W(n) = SUM[k = 1…n; k * T(k + 1)]

 

输入

The first line of input contains a single integer N, (1 ≤ N ≤ 1000) which is the number of datasets that follow.

Each dataset consists of a single line of input containing a single integer n, (1 ≤ n ≤300), which is the number of points on a side of the triangle.

输出

For each dataset, output on a single line the dataset number (1 through N), a blank, the value of n for the dataset, a blank, and the weighted sum ,W(n), of triangular numbers for n.

样例输入

4
3
4
5
10

样例输出

1 3 45
2 4 105
3 5 210
4 10 2145

来源

Greater New York 2006

上传者

张云聪

 

01.#include<stdio.h>

02.int WN(int n)

03.{

04.int i,sum=0;

05.for(i=1;i<n+1;i++)

06.{

07.sum+=i*((i+1)*(i+2))/2;

08.}

09.return sum;

10.}

11.int main()

12.{

13.int i,N,n,a[1000];

14.scanf("%d",&N);

15.for(i=0;i<N;i++)

16.{

17.scanf("%d",&a[i]);

18.}

19.for(i=0;i<N;i++)

20.{

21.printf("%d %d %d\n",i+1,a[i],WN(a[i]));

22.}

23. 

24.return 0;

25.}