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

434510

样例输出

1 3 452 4 1053 5 2104 10 2145

题意就是计算W（n）=1*T(1+1))+2*T(2+1)+3*T(3+1)+……+n*T(n+1),   n就是你输入的那个数

输出：         编号(就是输入的第几个n)，       n，          W（n）,理解了题意很好做

01.#include<iostream>

02. 

03.using namespace std;

04.int main()

05.{

06.int a[300],s[300],i,j=0;

07.a[0]=1;

08.s[0]=1;

09.for(i=1;i<=300;i++)

10.{

11.a[i]=a[i-1]+i+1;

12.s[i]=i*a[i];

13.}

14.int N;

15.cin>>N;

16.while(N--)

17.{

18.int n,sum=0;

19.cin>>n;

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

21.{

22.sum+=s[i];

23.}

24.j++;

25.cout<<j<<" "<<n<<" "<<sum<<endl;

26.}

27.return 0;

28.}