南阳oj 题目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

注：此题为：南阳oj 题目122 Triangular Sums

说明：公式代入：T(n) = 1 + … + n

                        W(n) = SUM[k = 1…n; k * T(k + 1)]

            注意输出格式

已AC源代码：

#include<iostream>using namespace std;int T_n(int k){int tn=0,i;for(i=1;i<=k;++i)    tn+=i;    return tn;}int main(){int N,temp=1;cin>>N;while(N--){int n,i,Wn,Tn,sum;cin>>n;sum=0;for(i=1;i<=n;++i){Tn=T_n(i+1);Wn=i*Tn;sum+=Wn;}cout<<temp++<<" "<<n<<" "<<sum<<endl;}return 0;}