Task: 2048






PHP: <?php

$game = new Game();

while(true) {
    $game->cycle();
}

class Game {
	private $field;
	private $fieldSize;
	private $command;
	private $error;
	private $lastIndexX, $lastIndexY;
	private $score;
	private $finishScore;

	function __construct() {
		$this->field = array();
		$this->fieldSize = 4;
		$this->finishScore = 2048;
		$this->score = 0;
		$this->addNumber();
		$this->render();
	}

	public function cycle() {
		$this->command = strtolower($this->readchar('Use WASD, q exits'));
		$this->cls();

		if($this->processCommand()) {
			$this->addNumber();
		} else {
			if(count($this->getFreeList()) == 0 ) {
				$this->error = 'No options left!, You Lose!!';
			} else {
				$this->error = 'Invalid move, try again!';
			}
		}
		$this->render();
	}

	private function readchar($prompt) {
		readline_callback_handler_install($prompt, function() {});
		$char = stream_get_contents(STDIN, 1);
		readline_callback_handler_remove();
		return $char;
	}

	
	private function addNumber() {
		$freeList = $this->getFreeList();
		if(count($freeList) == 0) {
			return;
		}
		$index = mt_rand(0, count($freeList)-1);
		$nr = (mt_rand(0,9) == 0)? 4 : 2;
		$this->field[$freeList[$index]['x']][$freeList[$index]['y']] = $nr;
		return;
	}

	
	private function getFreeList() {
		$freeList = array();
		for($y =0; $y< $this->fieldSize;$y++) {
			for($x=0; $x < $this->fieldSize; $x++) {
				if(!isset($this->field[$x][$y])) {
					$freeList[] = array('x' => $x, 'y' => $y);
				} elseif($this->field[$x][$y] == $this->finishScore) {
					$this->error = 'You Win!!';
				}
			}
		}
		return $freeList;
	}

	
	private function processCommand() {
		if(!in_array($this->command, array('w','a','s','d','q'))) {
			$this->error = 'Invalid Command';
			return false;
		}
		if($this->command == 'q') {
			echo PHP_EOL. 'Bye!'. PHP_EOL;
			exit;
		}

		$axis = 'x';
		$sDir = 1;

		switch($this->command) {
			case 'w':
				$axis = 'y';
				$sDir = -1;
				break;
			case 'a':
				$sDir = -1;
				break;
			case 's':
				$axis = 'y';
				break;
			case 'd':
			break;
		}

		$done = 0;

		$done += $this->shift($axis, $sDir);

		$done += $this->merge($axis, $sDir * -1);

		$done += $this->shift($axis, $sDir);
		return $done >0;
	}

	private function shift($axis, $dir) {
		$totalDone = 0;
		for($i = 0; $i <$this->fieldSize; $i++) {
			$done = 0;
			foreach($this->iterate($axis,$dir) as $xy) {
				if($xy['vDest'] === NULL && $xy['vSrc'] !== NULL) {
					$this->field[$xy['dX']][$xy['dY']] = $xy['vSrc'];
					$this->field[$xy['sX']][$xy['sY']] = NULL;
					$done++;
				}
			}
			$totalDone += $done;
			if($done == 0) {

				break;
			}
		}
		return $totalDone;
	}

	private function merge($axis, $dir) {
		$done = 0;
		foreach($this->iterate($axis,$dir) as $xy) {
			if($xy['vDest'] !== NULL && $xy['vDest'] === $xy['vSrc']) {
				$this->field[$xy['sX']][$xy['sY']] += $xy['vDest'];
				$this->field[$xy['dX']][$xy['dY']] = NULL;
				$this->score += $this->field[$xy['sX']][$xy['sY']];
				$done ++;
			}
		}
		return $done;
	}

	
	private function iterate($axis, $dir) {
		$res = array();
		for($y = 0; $y < $this->fieldSize; $y++) {
			for($x=0; $x < $this->fieldSize; $x++) {
				$item = array('sX'=> $x,'sY' => $y, 'dX' => $x, 'dY' => $y, 'vDest' => NULL,'vSrc' => NULL);
				
				if($axis == 'x') {
					$item['dX'] += $dir;
				} else {
					$item['dY'] += $dir;
				}

				if($item['dX'] >= $this->fieldSize || $item['dY'] >=$this->fieldSize || $item['dX'] < 0 || $item['dY'] < 0) {
					continue;
				}

				$item['vDest'] = (isset($this->field[$item['dX']][$item['dY']]))? $this->field[$item['dX']][$item['dY']] : NULL;
				$item['vSrc'] = (isset($this->field[$item['sX']][$item['sY']]))? $this->field[$item['sX']][$item['sY']] : NULL;
				$res[] = $item;
			}
		}
		if($dir < 0) {
			$res = array_reverse($res);
		}
		return $res;
	}


	
	private function cls() {
		echo chr(27).chr(91).'H'.chr(27).chr(91).'J';
	}

	private function render() {
		echo $this->finishScore . '! Current score: '. $this->score .PHP_EOL;

		if(!empty($this->error)) {
			echo $this->error . PHP_EOL;
			$this->error = NULL;
		}
		$this->renderField();
	}

	private function renderField() {
		$width = 5;
		$this->renderVSeperator($width);
		for($y =0; $y < $this->fieldSize; $y ++) {
			for($x = 0;$x < $this->fieldSize; $x++) {
				echo '|';
				if(!isset($this->field[$x][$y])) {
					echo str_repeat(' ', $width);
					continue;
				}
				printf('%'.$width.'s', $this->field[$x][$y]);
			}
			echo '|'. PHP_EOL;
			$this->renderVSeperator($width);
		}
	}

	private function renderVSeperator($width) {
		echo str_repeat('+'. str_repeat('-', $width), $this->fieldSize) .'+' .PHP_EOL;
	}

}






Ada: with Ada.Text_IO; use Ada.Text_IO;
with System.Random_Numbers;
procedure Play_2048 is
   
   type t_Keystroke is (Up, Down, Right, Left, Quit, Restart, Invalid);
   
   function Get_Immediate return Character is
   begin
      return Answer : Character do Ada.Text_IO.Get_Immediate(Answer);
      end return;
   end Get_Immediate;
   Arrow_Prefix : constant Character := Character'Val(224); 
   function Get_Keystroke return t_Keystroke is
     (case Get_Immediate is
         when 'Q' | 'q' => Quit,
         when 'R' | 'r' => Restart,
         when 'W' | 'w' => Left,
         when 'A' | 'a' => Up,
         when 'S' | 's' => Down,
         when 'D' | 'd' => Right,
         
         when Arrow_Prefix => (case Character'Pos(Get_Immediate) is
                                  when 72 => Up,
                                  when 75 => Left,
                                  when 77 => Right,
                                  when 80 => Down,
                                  when others => Invalid),
         
         when ASCII.ESC => (case Get_Immediate is
                               when '[' => (case Get_Immediate is
                                               when 'A' => Up,
                                               when 'B' => Down,
                                               when 'C' => Right,
                                               when 'D' => Left,
                                               when others => Invalid),
                               when others => Invalid),
         when others => Invalid);
 
   
   function Random_Int is new System.Random_Numbers.Random_Discrete(Integer);
   type    t_List  is array (Positive range <>) of Natural;
   subtype t_Row   is t_List (1..4);
   type    t_Board is array  (1..4) of t_Row;
   Board     : t_Board;
   New_Board : t_Board;
   Blanks    : Natural;
   Score     : Natural;
   Generator : System.Random_Numbers.Generator;
 
   
   procedure Display_Board is
      Horizontal_Rule : constant String := "+
      function Center (Value : in String) return String is
        ((1..(2-(Value'Length-1)/2) => ' ') & 
         Value(Value'First+1..Value'Last)   & 
         (1..(2-Value'Length/2) => ' '));     
   begin
      Put_Line (Horizontal_Rule);
      for Row of Board loop
         for Cell of Row loop
            Put('|' & (if Cell = 0 then "    " else Center(Cell'Img)));
         end loop;
         Put_Line("|");
         Put_Line (Horizontal_Rule);
      end loop;
      Put_Line("Score =" & Score'Img);
   end Display_Board;
 
   
   procedure Add_Block is
      Block_Offset : Positive := Random_Int(Generator, 1, Blanks);
   begin
      Blanks := Blanks-1;
      for Row of Board loop
         for Cell of Row loop
            if Cell = 0 then
               if Block_Offset = 1 then
                  Cell := (if Random_Int(Generator,1,10) = 1 then 4 else 2);
                  return;
               else
                  Block_Offset := Block_Offset-1;
               end if;
            end if;
         end loop;
      end loop;
   end Add_Block;
 
   procedure Reset_Game is
   begin
      Board  := (others => (others => 0));
      Blanks := 16;
      Score  := 0;
      Add_Block;
      Add_Block;
   end Reset_Game;
 
   
   function HFlip (What : in t_Row) return t_Row is
     (What(4),What(3),What(2),What(1));
   function VFlip (What : in t_Board) return t_Board is
     (HFlip(What(1)),HFlip(What(2)),HFlip(What(3)),HFlip(What(4)));
   function Transpose (What : in t_Board) return t_Board is
   begin
      return Answer : t_Board do
         for Row in t_Board'Range loop
            for Column in t_Row'Range loop
               Answer(Column)(Row) := What(Row)(Column);
            end loop;
         end loop;
      end return;
   end Transpose;
 
   
   
   function Add_Blank (Delta_Score : in Natural) return t_List is
   begin
      Blanks := Blanks+1;
      Score  := Score+Delta_Score;
      return (1 => 0);
   end Add_Blank;
 
   function Move_Row (What : in t_List) return t_List is
     (if What'Length = 1 then What
      elsif What(What'First) = 0
      then Move_Row(What(What'First+1..What'Last)) & (1 => 0)
      else (1 => What(What'First)) & Move_Row(What(What'First+1..What'Last)));
 
   function Merge (What : in t_List) return t_List is
     (if What'Length <= 1 or else What(What'First) = 0 then What
      elsif What(What'First) = What(What'First+1)
      then (1 => 2*What(What'First)) & Merge(What(What'First+2..What'Last)) & Add_Blank(What(What'First))
      else (1 => What(What'First)) & Merge(What(What'First+1..What'Last)));
 
   function Move (What : in t_Board) return t_Board is
     (Merge(Move_Row(What(1))),Merge(Move_Row(What(2))),Merge(Move_Row(What(3))),Merge(Move_Row(What(4))));
 
begin
   System.Random_Numbers.Reset(Generator);
   
   Main_Loop: loop
      Reset_Game;
      Game_Loop: loop    
         Display_Board;
         case Get_Keystroke is
            when Restart => exit Game_Loop;
            when Quit    => exit Main_Loop;
            when Left    => New_Board := Move(Board);
            when Right   => New_Board := VFlip(Move(VFlip(Board)));
            when Up      => New_Board := Transpose(Move(Transpose(Board)));
            when Down    => New_Board := Transpose(VFlip(Move(VFlip(Transpose(Board)))));
            when others  => null;
         end case;
         
         if New_Board = Board then
            Put_Line ("Invalid move...");
         elsif (for some Row of New_Board => (for some Cell of Row => Cell = 2048)) then
            Display_Board;
            Put_Line ("Win !");
            exit Main_Loop;
         else
            Board := New_Board;
            Add_Block; 
            if Blanks = 0
               and then (for all Row in 1..4 =>
                           (for all Column in 1..3 =>
                                (Board(Row)(Column) /= Board(Row)(Column+1))))
               and then (for all Row in 1..3 =>
                           (for all Column in 1..4 =>
                                (Board(Row)(Column) /= Board(Row+1)(Column)))) then
               Display_Board;
               Put_Line ("Lost !");
               exit Main_Loop;
            end if;
         end if;
      end loop Game_Loop;
   end loop Main_Loop;
end Play_2048;