// 15-Puzzle
   // Written by: Deepak Kumar
   // November 2019
   // Purpose: Program to play the 15-puzzle
   // It displays a 15-puzzle
   // Then the user can shuffle the tiles by pressing the 's' key.
   // Using the arrow keys, the user can move the "blank" tile up, down, left, or right

Board puzzle;    // The puzzle board

void setup() {
   fullScreen();
   puzzle = new Board();    // Create a fresh puzzle (solved)
   puzzle.printBoard();
   } // setup()

void draw() {
   background(255);
   puzzle.display();
   } // draw()

void keyPressed() {
   // User interaction
   // pressing key 's' (code 83) shuffles the puzzle
   if (keyCode == 83) puzzle.shuffle();
   // pressing arrow keys will make the requested move: up, down, left, right
   // Any key other than arrow is ignored
   // also if a move cannot be made, it does nothing
   puzzle.move(keyCode);
   puzzle.display();
   } // keyPressed()