Spiral Rectangle of Numbers

This program prints a rectangular spiral of numbers.

Problem Statement

Write a Java program that prints a 4x6 rectangle filled with numbers in spiral order.

Source Code

1 public class SpiralRectangleNumbers {
2 public static void main(String[] args) {
3 int rows=4, cols=6;
4 int[][] arr=new int[rows][cols];
5 int top=0, left=0, bottom=rows-1, right=cols-1, num=1;
6 while(top<=bottom && left<=right) {
7 for(int i=left; i<=right; i++) arr[top][i]=num++;
8 top++;
9 for(int i=top; i<=bottom; i++) arr[i][right]=num++;
10 right--;
11 for(int i=right; i>=left; i--) arr[bottom][i]=num++;
12 bottom--;
13 for(int i=bottom; i>=top; i--) arr[i][left]=num++;
14 left++;
15 }
16 for(int i=0; i<rows; i++) {
17 for(int j=0; j<cols; j++) System.out.print(arr[i][j] + "\t");
18 System.out.println();
19 }
20 }
21 }

Program Output

1   2   3   4   5   6   
14  15  16  17  18  7   
13  20  19  22  21  8   
12  11  10  9   24  23  

Explanation

The same spiral fill logic as the square version is applied to a non-square 4x6 matrix, showing that spiral logic adapts naturally to rectangular grids of different row and column counts.

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