- 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):
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X
X X
X X X
X X X XWrite 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 ",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 }