programming

Question

programming

Manu · Accepted Answer

Step 1:

By simulating a simplified chessboard, this Java application enables some chess pieces to move in accordance with fundamental chess principles. An 8x8 board is first set up by the computer with preset pieces—such as pawns, bishops, and rooks—positioned at predetermined locations. The move instructions, which specify the piece type and its start and finish locations, are read from an external file (input2.txt). Then, using the piece's movement rules—for example, bishops move diagonally while pawns may only advance one square—the software verifies the correctness of each move. While erroneous movements show an error message, valid moves update the board. Each rank and file is labelled for convenient access, and the board state is printed after each move in a style that resembles a conventional chequerboard arrangement. Java file handling, conditional logic, and array manipulation may all be learnt using this application, which acts as an introduction to object movement and validation logic in a grid-based system.

import java.io.*;

public class Main {
    private static char[][] board;

    public static void main(String[] args) throws IOException {
        initializeBoard();
        readMoves("src/main/java/input2.txt");  // Adjust the path as needed
    }

    private static void initializeBoard() {
        board = new char[8][8];

        // Set initial positions to match the desired output
        board[6][1] = 'r';  // Rook at (6,1)
        board[5][2] = 'b';  // Bishop at (5,2)
        board[5][5] = 'p';  // Pawn at (5,5)
        board[4][1] = 'r';  // Rook at (4,1)
        board[3][5] = 'b';  // Bishop at (3,5)
        board[2][5] = 'p';  // Pawn at (2,5)
        board[1][3] = 'h';  // Knight at (1,3)
        board[1][4] = 'r';  // Rook at (1,4)
        board[0][2] = 'h';  // Knight at (0,2)
    }

    private static void readMoves(String fileName) throws IOException {
        BufferedReader br = new BufferedReader(new FileReader(fileName));
        String line;

        while ((line = br.readLine()) != null) {
            System.out.println(line);  // Print the move instruction, e.g., "PAWN: (7,0) (7,2)"
            processMove(line);
            displayBoard();
        }

        br.close();
    }

    private static void processMove(String move) {
        String[] parts = move.split(": ");
        String pieceType = parts[0];
        String[] coordinates = parts[1].split(" ");

        // Extract start and end coordinates
        int startX = Integer.parseInt(coordinates[0].substring(1, 2));
        int startY = Integer.parseInt(coordinates[0].substring(3, 4));
        int endX = Integer.parseInt(coordinates[1].substring(1, 2));
        int endY = Integer.parseInt(coordinates[1].substring(3, 4));

        char piece = board[startX][startY];

        if (isValidMove(pieceType, startX, startY, endX, endY)) {
            System.out.println("Moved! (" + startX + "," + startY + ") (" + endX + "," + endY + ")");
            makeMove(piece, startX, startY, endX, endY);
        } else {
            System.out.println("Invalid move. (" + startX + "," + startY + ") (" + endX + "," + endY + ")");
        }
    }

    private static boolean isValidMove(String pieceType, int startX, int startY, int endX, int endY) {
        if (pieceType.equals("PAWN")) {
            // Pawn moves forward one step vertically
            return startY == endY && (endX == startX - 1);
        } else if (pieceType.equals("BISHOP")) {
            // Bishop moves diagonally
            return Math.abs(startX - endX) == Math.abs(startY - endY);
        }
        return false;
    }

    private static void makeMove(char piece, int startX, int startY, int endX, int endY) {
        board[startX][startY] = '-';  // Clear the old position
        board[endX][endY] = piece;    // Place the piece at the new position
    }

    private static void displayBoard() {
        System.out.println("=================================");
        for (int i = 7; i >= 0; i--) {
            System.out.print("=" + i + "= ");
            for (int j = 0; j < 8; j++) {
                System.out.print((board[i][j] == 0 ? "-" : board[i][j]) + " ");
            }
            System.out.println();
        }
        System.out.println("=== =0= =1= =2= =3= =4= =5= =6= =7=");
        System.out.println("=================================");
    }
}

Explanation:

By reading and verifying movements from a file, updating the board for moves that are legitimate, and displaying the board state after each move, this Java application replicates a chessboard.

Computer science

Computer science

Manu

Answer

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