1411030903-ny-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

题目大意

       根据那个公式来求，没有什么难度。

代码

#include<stdio.h>
int num[350];
int main()
{
    int t,n;
	int i,j,sum;
	num[0]=0;
	for(i=1;i<=330;i++)
	    num[i]=num[i-1]+i;
	scanf("%d",&t);
	j=1;
	while(t--)
	{
	    scanf("%d",&n);
		sum=0;
		for(i=1;i<=n;i++)
		sum+=i*num[i+1];
		printf("%d %d %d\n",j,n,sum);
		j++;
	} 
	return 0;
}