27_maze.rb

require 'matrix'

class Maze
    # List of valid moves, each mapped to a row and column offset hash
    # eg. moving north means going up one row (-1 rows, 0 columns) in the maze array
    @@valid_moves = {
        'N': { row: -1, col: 0 },
        'S': { row: 1, col: 0 },
        'E': { row: 0, col: 1 },
        'W': { row: 0, col: -1 }
    }

    def initialize(maze)
        @maze = maze
        # Find the start location (element with value 2)
        # First find the row that includes the value 2
        start_row = maze.find { |row| row.include?(2) }
        # Construct player position hash from column and row indexes
        @player_position = { col: start_row.index(2), row: maze.index(start_row) }
    end
    def walk(moves)
        for move in moves do
            # Convert move to symbol so we can use it to reference @@valid_moves
            move = move.to_sym
            # Ignore invalid moves
            if @@valid_moves[move]
                # Adjust the player position according to the direction moved
                @player_position[:col] += @@valid_moves[move][:col]
                @player_position[:row] += @@valid_moves[move][:row]
                # Get the value at the new location in the maze
                # This will fail if we're outside the maze, triggering the rescue clause
                value = @maze[@player_position[:row]][@player_position[:col]]
                # Hit a wall?
                return 'Dead' if value == 1
                # Reached the exit?
                return 'Finish' if value == 3
            end
        end
        # If we didn't finish or die, then we're lost!
        'Lost'
    rescue
        'Dead'
    end
end