using System;

using System.Collections.Generic;

public class MartixTraversal

{

    public static void Main()

    {

        string spiralPrint = Traversal([1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25], 5, 5);

        //string spiralPrint = Traversal([1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36], 6, 6);

​

        Console.WriteLine(spiralPrint);

    }

    static string Traversal(int[] matrix, int rows, int columns)

    {

        string res = "";

        bool[, ] printed = new bool[rows, columns];

        int[,] resultMatrix = new int[rows, columns];

        // Turn the vector into a 2d array

        for(int a = 0; a < rows; a++) {

            for(int b = 0; b < columns; b++) {

                resultMatrix[a, b] = matrix[b + a * columns];

            }

        }

        // Direction vectors, ex: row 0, column 1 -> (0,1) (0,2) (0,3) / row 1, column 0 -> (4,1) (4,2) (4,3 (4,4)

        int[] rowsDir = [ 0, 1, 0, -1 ];

        int[] columnsDir = [ 1, 0, -1, 0 ];

        int validRow = 0;

        int validColumn = 0; 

        int dirIndex = 0;

        for (int i = 0; i < rows * columns; i++) {

            res += resultMatrix[validRow, validColumn] + " ";

            // Mark the value printed to turn the direction

            printed[validRow, validColumn] = true;

            // Iterate the matrix

            int candidateRow = validRow + rowsDir[dirIndex];

            int candidateColumn = validColumn + columnsDir[dirIndex];

​

            // If the candidate row and column are greater than 0, are not printed and are in bounds of the matrix, the candidate value is valid

            if (candidateRow >= 0  && candidateColumn >= 0 && candidateRow < rows &&  candidateColumn < columns && !printed[candidateRow, candidateColumn]) {

                validRow = candidateRow;

                validColumn = candidateColumn;

            }

            // When the candidate value isnt valid, we turn directions between the 4 options (up, down, left, right)

            else {

                dirIndex = (dirIndex + 1) % 4;

                validRow += rowsDir[dirIndex];

                validColumn += columnsDir[dirIndex];

            }

        }

        return res;

    }

}

​

​

​