308
技術社區[雲棲]
Triangular Sums
Triangular Sums
時間限製：3000 ms | 內存限製：65535 KB
難度：2
- 描述
-
The nth 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)]- 輸入
- 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. - 輸出
- 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.
- 樣例輸入
-
4 3 4 5 10
- 樣例輸出
-
1 3 45 2 4 105 3 5 210 4 10 2145
01.#include <iostream>
02.using
namespace std;
03.
04.int
main()
05.{
06.int
testNum;
07.cin >> testNum;
08.
09.for
(int
sample = 1; sample <= testNum; sample++)
10.{
11.long
w = 0;
12.int
n;
13.cin >> n;
14.for
(int
k = 1; k <= n; k++)
15.{
16.//等差公式
17.w += k * ((1+(k+1)) * (k+1) / 2);
18.}
19.cout << sample <<
" " << n << " "
<< w << endl;
20.}
21.
22.return
0;
23.}
最後更新：2017-04-03 05:40:23