Spiral Display of 2D Array

package jan22;

import java.util.Scanner;

public class SpiralDisplay {

    public static void main(String[] args) {

        // Declare a 2D array with 3 rows and 4 columns
        // Space Complexity: O(m * n), where m = 3, n = 4
        int[][] arr = new int[3][4];

        Scanner scanner = new Scanner(System.in);  // Constant space (O(1)) for Scanner object

        // Input loop to fill the 2D array
        // Time Complexity: O(m * n), every element is read once
        for (int i = 0; i < arr.length; i++) {              // Loop over m rows
            for (int j = 0; j < arr[0].length; j++) {       // Loop over n columns
                arr[i][j] = scanner.nextInt();              // Input each element (O(1))
            }
        }

        spiralDisplay(arr); // Call method to print in diagonal wave order
    }

    private static void spiralDisplay(int[][] arr) {

        int column = 0;

        // First phase: traverse from top row diagonally down-right
        // Total iterations: m diagonals from first column
        for (int row = 0; row < arr.length; row++) {
            int tempRow = row, tempCol = column;
            while (tempRow >= 0 && tempCol < arr[0].length) { // Stay within bounds
                System.out.print(arr[tempRow--][tempCol++] + " ");  // Diagonal up-left
            }
        }

        int row = arr.length - 1;

        // Second phase: traverse from top row's second column to end, diagonally
        for (int col = 1; col < arr[0].length; col++) {
            int tempRow = row, tempCol = col;
            while (tempCol < arr[0].length && tempRow >= 0) { // Stay within bounds
                System.out.print(arr[tempRow--][tempCol++] + " ");  // Diagonal up-left
            }
        }
    }
}


Complexity
Best Case
Average Case
Worst Case
Explanation
TC
O(m × n)
O(m × n)
O(m × n)
Each element is printed exactly once diagonally
SC
O(m × n)
O(m × n)
O(m × n)
For storing input array; no extra space used