Triangular Sums

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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

 1 #include <stdio.h> 
 2 
 3 int sum(int n);
 4 
 5 int main(){
 6     int T;
 7     int n;
 8     int i;
 9     int result;
10     int time;
11     
12     time=1;
13     
14     scanf("%d",&T);
15     
16     while(T--){
17         scanf("%d",&n);
18         
19         result=0;
20         for(i=1;i<=n;i++)
21             result+=i*sum(i+1);
22         
23         printf("%d %d %d\n",time,n,result);    
24         time++;
25     }
26         
27     return 0;
28 }
29 
30 int sum(int n){
31     int i;
32     int result;
33     
34     result=0;
35     for(i=1;i<=n;i++)
36         result+=i;
37         
38     return result;
39 }

Triangular Sums

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原文地址：http://www.cnblogs.com/zqxLonely/p/4097970.html