KnightProject.java

import java.util.Scanner;

public class KnightProject {

    /**
    *   Program:    KnightProject.java
    *   Purpose:    Knight move problem for Yahoo! Answers
    *   Creator:    Chris Clarke
    *   Ceated:     01.06.2015
    */

    /*

    Print out a board with the size entered by user and the knight starting position entered by user.
    Then move the knight 3 steps from it's starting position.
    The knight's move should be labelled as 0(starting position), 1, 2, etc.

    */

    public static int size;
    public static int currRow, currCol;
    public static int moveCount = 0;
    public static int[][] board;

    public static boolean canGo(int r, int c) {
        if (r>=1 && r<=size && c>=1 && c<=size)
            return true;

        return false;
    }

    public static void makeMove(int r, int c) {
        board[r][c] = ++moveCount;
        currRow = r;
        currCol = c;
    }

    public static void displayBoard() {
        for (int r=1; r<=size; r++) {
            for (int c=1; c<=size; c++) {
                if (board[r][c] == -1) {
                    System.out.print(".");
                } else {
                    System.out.print(board[r][c]);
                } // if
            } // for c
            System.out.println();
        } // for r
        System.out.println();
    }

    public static void chooseMove(int r, int c) {
    // there are up to 8 possible knight moves
        if (canGo(r-2, c-1)) makeMove(r-2, c-1);    // 1
        else if (canGo(r-2,c+1)) makeMove(r-2, c+1);    // 2
        else if (canGo(r-1,c+2)) makeMove(r-1, c+2);    // 3
        else if (canGo(r+1,c+2)) makeMove(r+1,c+2); // 4
        else if (canGo(r+2,c+1)) makeMove(r+2,c+1); // 5
        else if (canGo(r+2,c-1)) makeMove(r+2,c-1); // 6
        else if (canGo(r+1,c-2)) makeMove(r+1,c-2); // 7
        else if (canGo(r-1,c-2)) makeMove(r-1,c-2); // 8
    }

    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        System.out.print("What size board would you like? ");
        size = scan.nextInt();
        board = new int[size+1][size+1];
        for (int r=1; r<=size; r++) {
            for (int c=1; c<=size; c++) {
                board[r][c] = -1;
            } // for c
        } // for r

        System.out.print("Place knight on which row (1-"+size+")? ");
        currRow = scan.nextInt();
        System.out.print("Place knight on which column (1-"+size+")? ");
        currCol = scan.nextInt();

        board[currRow][currCol] = 0;
        for (int i=0; i<3; i++) {
            chooseMove(currRow, currCol);
            displayBoard();
        } // for
    } // main()

} // class KnightProject