CMSC 256 Project 6

GoldKDB.java

/* Kevin Barbour
 * December 6, 2012
 * Project 6
 * 
 * Purpose: Find a path out of a field without running into any hedges or ogres
 * 	and collect gold along the way
 * Input: Filename in args[0], file contains dimensions of a field, contents
 * 	of the field and starting coordinates
 * Output: List of moves taken to find civilization, amount of gold found in
 * 	field, and number of minutes taken to find civilization
 */
import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.Scanner;
import java.util.Stack;

/* class Tile
 * Tile class for each coordinate on the map. Contains what is at the tile
 * and whether or not the tile has been visited
 */
class Tile {
	private char value;
	private boolean visited;

	public Tile(char value) {
		this.value = value;
		visited = false;
	}

	public char getValue() { return value; }
	public boolean isVisited() { return visited; }
	public void setVisit(boolean visited) { this.visited = visited; }
}

/* class Map
 * Contains a 2D array of tiles, the starting coordinates, and the dimensions
 * of the field
 */
class Map {
	private int rows, cols, start_row, start_col;
	private Tile[][] tiles;

	public Map(int rows, int cols, int start_row, int start_col, Tile[][] tiles) {
		this.rows = rows;
		this.cols = cols;
		this.start_row = start_row;
		this.start_col = start_col;
		this.tiles = tiles;
	}
	/* public void reset
	 * Method used to reset all tiles to unvisited so that map can be used
	 * again with second move method
	 */
	public void reset() {
		for(int i = 0; i < rows; i++)
			for(int j = 0; j < cols; j++)
				tiles[i][j].setVisit(false);
	}

	public Tile tileAt(int row, int col) { return tiles[row - 1][col - 1]; }
	public int get_rows() { return rows; }
	public int get_cols() { return cols; }
	public int get_start_row() { return start_row; }
	public int get_start_col() { return start_col; }
}

class Player {
	private int row, col, gold, minutes, start_row, start_col;
	private Stack<Character> moves;

	public Player(int start_row, int start_col) {
		this.start_row = start_row;
		this.start_col = start_col;
		row = start_row;
		col = start_col;
		gold = 0;
		minutes = 0;
		moves = new Stack<Character>();
	}
	
	/* public void reset
	 * Method to reset player to start row and column, return gold and minutes
	 * to zero, and make sure the moves stack is empty, so player can be used
	 * again with second move method
	 */
	public void reset() {
		row = start_row;
		col = start_col;
		gold = 0;
		minutes = 0;
		moves = new Stack<Character>();
	}

	/* public void print_info
	 * Method to print information about the player
	 * Moves taken, gold found, and minutes taken to find civilization
	 */
	public void print_info() {
		if(!moves.empty()) {
			while(true) {
				System.out.printf("%c", moves.pop());
				if(moves.empty()) break;
				else System.out.printf(",");
			}
		}

		System.out.println();
		System.out.printf("%d %d\n", gold, minutes);
	}

	public boolean moveNWES(Map map, int row_dir, int col_dir) {
		int new_row = row + row_dir;
		int new_col = col + col_dir;		

		// Check if location exists
		if(new_row < 1 || new_row > map.get_rows()) return false;
		if(new_col < 1 || new_col > map.get_cols()) return false;

		Tile cur_tile = map.tileAt(new_row, new_col);
		char value = cur_tile.getValue();

		// Make sure location can be moved to
		if(cur_tile.isVisited() == true || value == 'O' || value == 'H') return false;

		if(value == 'C') return true;
		if(value == 'G') gold++;

		// Mark the current tile as visited
		cur_tile.setVisit(true);
		row = new_row;
		col = new_col;

		minutes++;
		// Move north
		if(moveNWES(map, -1, 0)) { 
			moves.push('N');
			return true;
		}
		// Move west
		if(moveNWES(map, 0, -1)) {
			moves.push('W');
			return true;
		}
		// Move east
		if(moveNWES(map, 0, 1)) { 
			moves.push('E');
			return true;
		}
		// Move south
		if(moveNWES(map, 1, 0)) { 
			moves.push('S');
			return true;
		}
		// Backtracking
		minutes++;
		cur_tile.setVisit(false);
		if(value == 'G') gold--;
		row -= row_dir;
		col -= col_dir;
		return false;
	}
	
	public boolean moveSEWN(Map map, int row_dir, int col_dir) {
		int new_row = row + row_dir;
		int new_col = col + col_dir;		

		// Check if new location exists
		if(new_row < 1 || new_row > map.get_rows()) return false;
		if(new_col < 1 || new_col > map.get_cols()) return false;

		Tile cur_tile = map.tileAt(new_row, new_col);
		char value = cur_tile.getValue();

		// Check if new location can be moved to
		if(cur_tile.isVisited() == true || value == 'O' || value == 'H') return false;

		if(value == 'C') return true;
		if(value == 'G') gold++;

		// Mark the current tile as visited
		cur_tile.setVisit(true);
		row = new_row;
		col = new_col;

		minutes++;
		// Move south
		if(moveSEWN(map, 1, 0)) { 
			moves.push('S');
			return true;
		}
		// Move east
		if(moveSEWN(map, 0, 1)) { 
			moves.push('E');
			return true;
		}
		// Move west
		if(moveSEWN(map, 0, -1)) {
			moves.push('W');
			return true;
		}
		// Move north
		if(moveSEWN(map, -1, 0)) { 
			moves.push('N');
			return true;
		}
		// Backtracking
		minutes++;
		cur_tile.setVisit(false);
		if(value == 'G') { gold--; }
		row -= row_dir;
		col -= col_dir;
		return false;
	}
}

public class GoldKDB {
	public static void main(String[] args) throws FileNotFoundException, IOException {
		Map map = parseFile(args[0]);
		Player player = new Player(map.get_start_row(), map.get_start_col());

		player.moveNWES(map, 0, 0);
		player.print_info();
		
		map.reset();
		player.reset();
		
		player.moveSEWN(map, 0, 0);
		player.print_info();
	}

	static Map parseFile(String filename) throws FileNotFoundException, IOException {
		File input = new File(filename);
		Scanner file_scanner = new Scanner(input);
		int[] dimensions = {file_scanner.nextInt(), file_scanner.nextInt()};
		Tile[][] tiles = new Tile[dimensions[0]][dimensions[1]];
		String line;
		
		file_scanner.nextLine();
		
		for(int i = 0; i < dimensions[0]; i++) {
			line = file_scanner.nextLine();
			for(int j = 0; j < dimensions[1]; j++) {
				tiles[i][j] = new Tile(line.charAt(j));
			}
		}
		return new Map(dimensions[0], dimensions[1], file_scanner.nextInt(), file_scanner.nextInt(), tiles);
	}
}