南阳题目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

来源

就是直接计算就行了，公式就是W(n) = SUM[k = 1…n; k * T(k + 1)]







#include<cstdio>#include<cstring>#include<algorithm>using namespace std;int solve(int x){int i,sum=0;for(i=1;i<=x;i++)sum+=i;return sum;}int main(){int a,b,c,d,i,j,m,n,t,sum,cot=1;;scanf("%d",&m);while(m--){sum=0;scanf("%d",&a);for(i=1;i<=a;i++)sum+=i*solve(i+1);printf("%d %d %d\n",cot++,a,sum);}return 0;}