a) Complete your solution by developing Python code to replace the dummy follow_path function. You should complete your solution using only the standard Python 3 modules already imported by the provided template. Furthermore, you may not import any image files into your solution; the entire image must be drawn using Turtle graphics drawing primitives.

#-----Preamble-------------------------------------------------------#

# # This section imports necessary functions and defines constant # values used for creating the drawing canvas. You should not change # any of the code in this section. #

# Import the functions needed to complete this assignment. You # should not need to use any other modules for your solution. In # particular, your solution must not rely on any non-standard Python # modules that need to be downloaded and installed separately, # because the markers will not have access to such modules.

from turtle import * from math import * from random import *

# Define constant values used in the main program that sets up # the drawing canvas. Do not change any of these values.

grid_size = 100 # pixels num_squares = 7 # to create a 7x7 map grid margin = 50 # pixels, the size of the margin around the grid legend_space = 400 # pixels, the space to leave for the legend window_height = grid_size * num_squares + margin * 2 window_width = grid_size * num_squares + margin + legend_space font_size = 18 # size of characters for the coords starting_points = ['Top left', 'Top right', 'Centre', 'Bottom left', 'Bottom right']

# #--------------------------------------------------------------------#

#-----Functions for Creating the Drawing Canvas----------------------# # # The functions in this section are called by the main program to # manage the drawing canvas for your image. You should not change # any of the code in this section. (Very keen students are welcome # to draw their own background, provided they do not change the map's # grid or affect the ability to see it.) #

# Set up the canvas and draw the background for the overall image def create_drawing_canvas(): # Set up the drawing window with enough space for the grid and # legend setup(window_width, window_height) setworldcoordinates(-margin, -margin, window_width - margin, window_height - margin)

# Draw as quickly as possible tracer(False)

# Choose a neutral background colour (if you want to draw your # own background put the code here, but do not change any of the # following code that draws the grid) bgcolor('light grey')

# Get ready to draw the grid penup() color('slate grey') width(2)

# Draw the horizontal grid lines setheading(0) # face east for y_coord in range(0, (num_squares + 1) * grid_size, grid_size): penup() goto(0, y_coord) pendown() forward(num_squares * grid_size) # Draw the vertical grid lines setheading(90) # face north for x_coord in range(0, (num_squares + 1) * grid_size, grid_size): penup() goto(x_coord, 0) pendown() forward(num_squares * grid_size)

# Draw each of the labels on the x axis penup() y_offset = -27 # pixels for x_coord in range(0, (num_squares + 1) * grid_size, grid_size): goto(x_coord, y_offset) write(str(x_coord), align = 'center', font=('Arial', font_size, 'normal'))

# Draw each of the labels on the y axis penup() x_offset, y_offset = -5, -10 # pixels for y_coord in range(0, (num_squares + 1) * grid_size, grid_size): goto(x_offset, y_coord + y_offset) write(str(y_coord), align = 'right', font=('Arial', font_size, 'normal'))

# Mark the space for drawing the legend goto((num_squares * grid_size) + margin, (num_squares * grid_size) // 2) write(' Put your legend here', align = 'left', font=('Arial', 24, 'normal'))

# Reset everything ready for the student's solution pencolor('black') width(1) penup() home() tracer(True)

# End the program and release the drawing canvas to the operating # system. By default the cursor (turtle) is hidden when the # program ends - call the function with False as the argument to # prevent this. def release_drawing_canvas(hide_cursor = True): tracer(True) # ensure any drawing still in progress is displayed #if hide_cursor: # hideturtle() done() # #--------------------------------------------------------------------#

#-----Test Data for Use During Code Development----------------------# # # The "fixed" data sets in this section are provided to help you # develop and test your code. You can use them as the argument to # the follow_path function while perfecting your solution. However, # they will NOT be used to assess your program. Your solution will # be assessed using the random_path function appearing below. Your # program must work correctly for any data set that can be generated # by the random_path function. # # Each of the data sets is a list of instructions expressed as # triples. The instructions have two different forms. The first # instruction in the data set is always of the form # # ['Start', location, token_number] # # where the location may be 'Top left', 'Top right', 'Centre', # 'Bottom left' or 'Bottom right', and the token_number is an # integer from 0 to 4, inclusive. This instruction tells us where # to begin our treasure hunt and the token that we find there. # (Every square we visit will yield a token, including the first.)

# The remaining instructions, if any, are all of the form # # [direction, number_of_squares, token_number] # # where the direction may be 'North', 'South', 'East' or 'West', # the number_of_squares is a positive integer, and the token_number # is an integer from 0 to 4, inclusive. This instruction tells # us where to go from our current location in the grid and the # token that we will find in the target square. See the instructions # accompanying this file for examples. #

# Some starting points - the following fixed paths just start a path # with each of the five tokens in a different location

fixed_path_0 = [['Start', 'Top left', 0]] fixed_path_1 = [['Start', 'Top right', 1]] fixed_path_2 = [['Start', 'Centre', 2]] fixed_path_3 = [['Start', 'Bottom left', 3]] fixed_path_4 = [['Start', 'Bottom right', 4]]

# Some miscellaneous paths which encounter all five tokens once

fixed_path_5 = [['Start', 'Top left', 0], ['East', 1, 1], ['East', 1, 2], ['East', 1, 3], ['East', 1, 4]] fixed_path_6 = [['Start', 'Bottom right', 0], ['West', 1, 1], ['West', 1, 2], ['West', 1, 3], ['West', 1, 4]] fixed_path_7 = [['Start', 'Centre', 4], ['North', 2, 3], ['East', 2, 2], ['South', 4, 1], ['West', 2, 0]]

# A path which finds each token twice

fixed_path_8 = [['Start', 'Bottom left', 1], ['East', 5, 2], ['North', 2, 3], ['North', 4, 0], ['South', 3, 2], ['West', 4, 0], ['West', 1, 4], ['East', 3, 1], ['South', 3, 4], ['East', 1, 3]]

# Some short paths

fixed_path_9 = [['Start', 'Centre', 0], ['East', 3, 2], ['North', 2, 1], ['West', 2, 3], ['South', 3, 4], ['West', 4, 1]]

fixed_path_10 = [['Start', 'Top left', 2], ['East', 6, 3], ['South', 1, 0], ['South', 1, 0], ['West', 6, 2], ['South', 4, 3]]

fixed_path_11 = [['Start', 'Top left', 2], ['South', 1, 0], ['East', 2, 4], ['South', 1, 1], ['East', 3, 4], ['West', 1, 3], ['South', 2, 0]]

# Some long paths

fixed_path_12 = [['Start', 'Top right', 2], ['South', 4, 0], ['South', 1, 1], ['North', 3, 4], ['West', 4, 0], ['West', 2, 0], ['South', 3, 4], ['East', 2, 3], ['East', 1, 1], ['North', 3, 2], ['South', 1, 3], ['North', 3, 2], ['West', 1, 2], ['South', 3, 4], ['East', 3, 0], ['South', 1, 1]]

fixed_path_13 = [['Start', 'Top left', 1], ['East', 5, 3], ['West', 4, 2], ['East', 1, 3], ['East', 2, 2], ['South', 5, 1], ['North', 2, 0], ['East', 2, 0], ['West', 1, 1], ['West', 5, 0], ['South', 1, 3], ['East', 3, 0], ['East', 1, 4], ['North', 3, 0], ['West', 1, 4], ['West', 3, 1], ['South', 4, 1], ['East', 5, 1], ['West', 4, 0]]

# "I've been everywhere, man!" - this path visits every square in # the grid, with randomised choices of tokens

fixed_path_99 = [['Start', 'Top left', randint(0, 4)]] + \ [['East', 1, randint(0, 4)] for step in range(6)] + \ [['South', 1, randint(0, 4)]] + \ [['West', 1, randint(0, 4)] for step in range(6)] + \ [['South', 1, randint(0, 4)]] + \ [['East', 1, randint(0, 4)] for step in range(6)] + \ [['South', 1, randint(0, 4)]] + \ [['West', 1, randint(0, 4)] for step in range(6)] + \ [['South', 1, randint(0, 4)]] + \ [['East', 1, randint(0, 4)] for step in range(6)] + \ [['South', 1, randint(0, 4)]] + \ [['West', 1, randint(0, 4)] for step in range(6)] + \ [['South', 1, randint(0, 4)]] + \ [['East', 1, randint(0, 4)] for step in range(6)]

# If you want to create your own test data sets put them here # #--------------------------------------------------------------------#

#-----Function for Assessing Your Solution---------------------------# # # The function in this section will be used to assess your solution. # Do not change any of the code in this section. # # The following function creates a random data set specifying a path # to follow. Your program must work for any data set that can be # returned by this function. The results returned by calling this # function will be used as the argument to your follow_path function # during marking. For convenience during code development and # marking this function also prints the path to be followed to the # shell window. # # Note: For brevity this function uses some Python features not taught # in IFB104 (dictionaries and list generators). You do not need to # understand this code to complete the assignment. # def random_path(print_path = True): # Select one of the five starting points, with a random token path = [['Start', choice(starting_points), randint(0, 4)]] # Determine our location in grid coords (assuming num_squares is odd) start_coords = {'Top left': [0, num_squares - 1], 'Bottom left': [0, 0], 'Top right': [num_squares - 1, num_squares - 1], 'Centre': [num_squares // 2, num_squares // 2], 'Bottom right': [num_squares - 1, 0]} location = start_coords[path[0][1]] # Keep track of squares visited been_there = [location] # Create a path up to 19 steps long (so at most there will be 20 tokens) for step in range(randint(0, 19)): # Find places to go in each possible direction, calculating both # the new grid square and the instruction required to take # us there go_north = [[[location[0], new_square], ['North', new_square - location[1], token]] for new_square in range(location[1] + 1, num_squares) for token in [0, 1, 2, 3, 4] if not ([location[0], new_square] in been_there)] go_south = [[[location[0], new_square], ['South', location[1] - new_square, token]] for new_square in range(0, location[1]) for token in [0, 1, 2, 3, 4] if not ([location[0], new_square] in been_there)] go_west = [[[new_square, location[1]], ['West', location[0] - new_square, token]] for new_square in range(0, location[0]) for token in [0, 1, 2, 3, 4] if not ([new_square, location[1]] in been_there)] go_east = [[[new_square, location[1]], ['East', new_square - location[0], token]] for new_square in range(location[0] + 1, num_squares) for token in [0, 1, 2, 3, 4] if not ([new_square, location[1]] in been_there)] # Choose a free square to go to, if any exist options = go_north + go_south + go_east + go_west if options == []: # nowhere left to go, so stop! break target_coord, instruction = choice(options) # Remember being there been_there.append(target_coord) location = target_coord # Add the move to the list of instructions path.append(instruction) # To assist with debugging and marking, print the list of # instructions to be followed to the shell window print('Welcome to the Treasure Hunt!') print('Here are the steps you must follow...') for instruction in path: print(instruction) # Return the random path return path

# #--------------------------------------------------------------------#

#-----Student's Solution---------------------------------------------# # # Complete the assignment by replacing the dummy function below with # your own "follow_path" function. # Follow the path as per the provided dataset