NYOJ--122--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

 

#include<stdio.h>
#define T(k) (k)*(k+1)/2 
int main()
{
    int N;
    int k = 0;
    scanf("%d",&N);
    while(N--){ 
        int n;
        int num = 0;
        scanf("%d",&n);
        for(int i=1;i<=n;i++)num +=i*T(i+1);
        k++;
        printf("%d %d %d\n",k,n,num);
    }
    return 0;
}