Matrix arrangement issues in php

Question

I would like to know some solutions to such a problem.

It is given a number lets say 16 and you have to arrange a matrix this way

1  2  3  4
12 13 14 5
         


        

Answer 1

Looks like the snake game might work. Track a direction vector, and turn right 90 degrees every time you hit a side or a populated square. The tail keeps extending indefinitely :)

Edit : Snakey v0.1 in C#. Works for non square grids too ;)

using System;
using System.Text;

namespace ConsoleApplication1
{
    class Program
    {
        public enum Direction
        {
            Up,
            Down,
            Left,
            Right
        }

        static void Main(string[] args)
        {
            int[,] maze;

            Direction currentDirection = Direction.Right;

            bool totallyStuck = false;
            bool complete = false;
            int currentX = 0;
            int currentY = 0;
            int boundX = 4;
            int boundY = 5;
            int currentNumber = 1;
            int stuckCounter = 0;
            bool placeNumber = true;

            maze = new int[boundY, boundX];

            while ((!totallyStuck) && (!complete))
            {
                if (placeNumber)
                {
                    maze[currentY, currentX] = currentNumber;
                    currentNumber++;
                    stuckCounter = 0;
                }

                switch (currentDirection)
                {
                    case Direction.Right:
                        // Noted short Circuit Bool Evan
                        if ((currentX + 1 < boundX) && (maze[currentY, currentX + 1] == 0))
                        {
                            placeNumber = true;
                            currentX++;
                            stuckCounter = 0;
                        }
                        else
                        {
                            placeNumber = false;
                            stuckCounter++;
                        }

                        break;
                    case Direction.Left:
                        if ((currentX - 1 >= 0) && (maze[currentY, currentX - 1] == 0))
                        {
                            placeNumber = true;
                            currentX--;
                            stuckCounter = 0;
                        }
                        else
                        {
                            placeNumber = false;
                            stuckCounter++;
                        }
                        break;
                    case Direction.Down:
                        if ((currentY + 1 < boundY) && (maze[currentY + 1, currentX] == 0))
                        {
                            placeNumber = true;
                            currentY++;
                            stuckCounter = 0;
                        }
                        else
                        {
                            placeNumber = false;
                            stuckCounter++;
                        }
                        break;
                    case Direction.Up:
                        if ((currentY - 1 >= 0) && (maze[currentY - 1, currentX] == 0))
                        {
                            placeNumber = true;
                            currentY--;
                            stuckCounter = 0;
                        }
                        else
                        {
                            placeNumber = false;
                            stuckCounter++;
                        }
                        break;
                }

                // Is Snake stuck? If so, rotate 90 degs right
                if (stuckCounter == 1)
                {
                    switch (currentDirection)
                    {
                        case Direction.Right:
                            currentDirection = Direction.Down;
                            break;
                        case Direction.Down:
                            currentDirection = Direction.Left;
                            break;
                        case Direction.Left:
                            currentDirection = Direction.Up;
                            break;
                        case Direction.Up:
                            currentDirection = Direction.Right;
                            break;
                    }
                }
                else if (stuckCounter > 1)
                {
                    totallyStuck = true;
                }
            }

            // Draw final maze
            for (int y = 0; y < boundY; y++)
            {
                for (int x = 0; x < boundX; x++)
                {
                    Console.Write(string.Format("{0:00} ",maze[y, x]));
                }
                Console.Write("\r\n");
            }
        }
    }
}