Low Level Design Snake & Ladder Game

Data Model

1. Game -> Board,Dice,Players
2. Board -> Cells
3. Cell -> Jump
4. Jump -> start, end
5. Player -> currentPosition
6. Dice -> number

Main.java :

public class Main {

    public static void main(String[] args) {
        Game game = new Game();
        game.startGame();
    }
}

Game.java :

package systemDesign.snakeAndLadderGame;

import java.util.Deque;
import java.util.LinkedList;

public class Game {

    private Board board;
    private Dice dice;
    private Player winner;
    private Deque<Player> playerList = new LinkedList<>();

    public Game(){
        intializeGame();
    }

    private void intializeGame() {
         board = new Board(10,5,4);
         dice = new Dice(1);
         winner = null;
         addPlayers();

    }

    private void addPlayers() {
        Player p1 = new Player(0);
        Player p2 = new Player(0);
        playerList.add(p1);
        playerList.add(p2);
    }

    public void startGame(){
        System.out.println("Game Begins......");
        while (winner == null){
            // Find Player
            Player currentPlayer = findCurrentPlayer();
            int diceNumber = dice.rollDice();
            int nextPosition = diceNumber + currentPlayer.getCurrentPosition();
            int finalPosition = checkIfJumpPossible(nextPosition);
            currentPlayer.setCurrentPosition(finalPosition);
            if(finalPosition > board.getCells().length * board.getCells().length -1){
                winner = currentPlayer;
                System.out.println("Game Over...");
            }


        }
    }

    private int checkIfJumpPossible(int nextPosition) {
        System.out.println("Checking for snake or ladder...");
        Cell cell = board.getCell(nextPosition);
        if(cell.getJump() != null && cell.getJump().start == nextPosition){
            return cell.getJump().end;
        }
        return nextPosition;

    }

    private Player findCurrentPlayer() {
        System.out.println("Selecting player to play...");
        Player currentPlayer = playerList.removeFirst();
        playerList.addLast(currentPlayer);
        return currentPlayer;
    }
}

Board.java :

package systemDesign.snakeAndLadderGame;

import java.util.concurrent.ThreadLocalRandom;

public class Board {

    private Cell[][] cells;

    public Cell[][] getCells() {
        return cells;
    }

    public Board(int boardSize, int snakes, int ladders) {
        intializeCells(boardSize);
        addSnakeAndLadders(snakes,ladders);

    }

    private void intializeCells(int boardSize) {
        cells = new Cell[boardSize][boardSize];
        for(int i = 0;i<boardSize;i++){
            for(int j = 0;j<boardSize;j++){
                Cell cell = new Cell();
                cells[i][j] = cell;
            }
        }
    }

    private void addSnakeAndLadders(int snakes, int ladders) {

        while (snakes > 0){
            int start = ThreadLocalRandom.current().nextInt(1,cells.length*cells.length-1);
            int end = ThreadLocalRandom.current().nextInt(1,cells.length*cells.length-1);
            if(start <= end){
                continue;
            }

            Jump jump = new Jump(start,end);
            Cell cell = getCell(start);
            cell.setJump(jump);
            snakes--;


        }

        while (ladders > 0){
            int start = ThreadLocalRandom.current().nextInt(1,cells.length*cells.length-1);
            int end = ThreadLocalRandom.current().nextInt(1,cells.length*cells.length-1);
            if(start <= end){
                continue;
            }

            Jump jump = new Jump(start,end);
            Cell cell = getCell(start);
            cell.setJump(jump);
            ladders--;
        }
    }

    public Cell getCell(int playerPosition) {
        int start = playerPosition / cells.length;
        int end = playerPosition % cells.length;
        return cells[start][end];
    }
}

Cell.java :

package systemDesign.snakeAndLadderGame;

public class Cell {

    private Jump jump;

    public Jump getJump() {
        return jump;
    }

    public void setJump(Jump jump) {
        this.jump = jump;
    }
}

Dice.java :

package systemDesign.snakeAndLadderGame;

import java.util.concurrent.ThreadLocalRandom;

public class Dice {

    private int count;
    private int max = 6;
    private int min = 1;

    public Dice(int count) {
        this.count = count;
    }

    public int rollDice(){
        System.out.println("Dice rolling...");
        int diceUsed = 0;
        int result = 0;

        while (diceUsed < count){
            result += ThreadLocalRandom.current().nextInt(min,max);
            diceUsed++;
        }

        return result;
    }
}

Jump.java :

package systemDesign.snakeAndLadderGame;

public class Jump {

    int start;
    int end;

    public Jump(int start, int end) {
        this.start = start;
        this.end = end;
    }
}

Player.java :

package systemDesign.snakeAndLadderGame;

public class Player {

    private int currentPosition;

    public Player(int currentPosition) {
        this.currentPosition = currentPosition;
    }

    public int getCurrentPosition() {
        return currentPosition;
    }

    public void setCurrentPosition(int currentPosition) {
        this.currentPosition = currentPosition;
    }
}

Thanks for reading. Happy Learning !!