poj3086Triangular Sums

Time Limit: 1000MS		Memory Limit: 65536K
Total Submissions: 6286		Accepted: 4466

Description

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)]

Input

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.

Output

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.

Sample Input

4
3
4
5
10

Sample Output

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

Source

Greater New York 2006

代码：

#include <iostream>
#include <stdio.h>
using namespace std;
int main()
{
int i,n;
   double k,ans;
scanf("%d",&n);
for(i=1;i<=n;++i)
{
scanf("%lf",&k);
ans=k*(k+1)*(k+2)*(k+3)/8;
printf("%d %.lf %.lf\n",i,k,ans);
}
return 0;
}