Triangular Sums
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
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
1 import java.text.NumberFormat; 2 import java.util.Arrays; 3 import java.util.Scanner; 4 5 public class Main { 6 public static void main(String[] args) { 7 Scanner scanner=new Scanner(System.in); 8 int T; 9 int n; 10 int k; 11 int i; 12 int temp; 13 int sum; 14 int time=1; 15 16 T=scanner.nextInt(); 17 while(true){ 18 if(T==0) 19 break; 20 T--; 21 22 n=scanner.nextInt(); 23 24 sum=0; 25 for(k=1;k<=n;k++){ 26 temp=0; 27 for(i=1;i<=k+1;i++) 28 temp+=i; 29 30 sum+=k*temp; 31 } 32 System.out.println(time+" "+n+" "+sum); 33 time++; 34 } 35 } 36 }