Spiral Triangle of Numbers
This program prints a triangular spiral of numbers.
Problem Statement
Write a Java program that prints a triangle of 5 rows filled with numbers in spiral order.
Source Code
| 1 | public class SpiralTriangleNumbers { |
| 2 | public static void main(String[] args) { |
| 3 | int n=5; |
| 4 | int[][] arr=new int[n][n]; |
| 5 | int num=1; |
| 6 | for(int i=0;i<n;i++){ |
| 7 | for(int j=0;j<=i;j++){ |
| 8 | arr[i][j]=num++; |
| 9 | } |
| 10 | } |
| 11 | for(int i=0;i<n;i++){ |
| 12 | for(int j=0;j<=i;j++){ |
| 13 | System.out.print(arr[i][j]+" "); |
| 14 | } |
| 15 | System.out.println(); |
| 16 | } |
| 17 | } |
| 18 | } |
Program Output
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Explanation
A running counter num fills a triangular section of the matrix row by row, so the triangle is filled with a straightforward sequential progression rather than a boundary-based spiral.