Triangular Sums
时间限制：
3000 ms | 内存限制：
65535 KB
难度：
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)]- 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
#include<stdio.h>
int sum(int a)
{
int b=0,i;
for(i=1;i<=a;i++)
{
b+=i;
}
return b;
}
int f(int n)
{
int sum1=0;
int i;
for(i=1;i<=n;i++)
{
sum1+=i*sum(i+1);
}
return sum1;
}
int main()
{
int n,t;
int i=1;
scanf("%d",&n);
while(n--)
{
scanf("%d",&t);
printf("%d %d %d\n",i,t,f(t));
i++;
}
return 0;
}