Write a Program to display Matrix in a Wave like form – Nagarro Interview Question

This is one of the subjective programming question of Nagarro.

using System;

namespace MatrixWave
{
    class Program
    {
        int[,] mat = new int[3, 3];

        static void Main(string[] args)
        {
            Program p1 = new Program();
            p1.Input();
            Console.WriteLine("The Inputed Matrix ::");
            p1.Show();
            Console.WriteLine(":: Output ::");
            p1.Wave();
            Console.ReadLine();
        }

        /// <summary>
        /// For taking input from user for the matrix
        /// </summary>
        public void Input()
        {
            Console.WriteLine("Enter 9 elements for a 3X3 Matrix");
            for (int i = 0; i < 3; i++)
            {
                for (int j = 0; j < 3; j++)
                {
                    mat[i, j] = Convert.ToInt32(Console.ReadLine());
                }
            }
        }

        /// <summary>
        /// Show the inputted elements in matrix form
        /// </summary>
        public void Show()
        {
            for (int i = 0; i < 3; i++)
            {
                for (int j = 0; j < 3; j++)
                {
                    Console.Write(mat[i, j] + "\t");
                }
                Console.WriteLine("\n");
            }
        }

        /// <summary>
        /// Show the matrix in a wave like form
        /// </summary>
        public void Wave()
        {
            int j = 0;
            int count = 0;

            do
            {
                int i = 0;
                if (j < 3)
                {
                    for (int line = 0; line < 3; line++)
                    {
                        Console.Write(mat[i, j] + "   ");
                        i++; count++;
                    }
                }
                i = 2; j++;
                if (j < 3)
                {
                    for (int line = 0; line < 3; line++)
                    {
                        Console.Write(mat[i, j] + "   ");
                        i--; count++;
                    }
                    j++;
                }
            } while (count < 9);
        }
    }
}