question39.java

import java.util.*;

public class question39 {
    
    public static List<Integer> spiralOrder(int[][] matrix) {
        List<Integer> result = new ArrayList<>();
        
        if (matrix == null || matrix.length == 0) return result;

        int top = 0;
        int bottom = matrix.length - 1;
        int left = 0;
        int right = matrix[0].length - 1;

        while (top <= bottom && left <= right) {

            for (int i = left; i <= right; i++)
                result.add(matrix[top][i]);
            top++;
            for (int i = top; i <= bottom; i++)
                result.add(matrix[i][right]);
            right--;
            if (top <= bottom) {
                for (int i = right; i >= left; i--)
                    result.add(matrix[bottom][i]);
                bottom--;
            }
            if (left <= right) {
                for (int i = bottom; i >= top; i--)
                    result.add(matrix[i][left]);
                left++;
            }
        }

        return result;
    }

    public static void main(String[] args) {
        int[][] matrix = {
            {1,  2,  3,  4},
            {5,  6,  7,  8},
            {9, 10, 11, 12}
        };

        List<Integer> spiral = spiralOrder(matrix);
        System.out.println("Spiral Order: " + spiral);
      }  
         


    }