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6.3 KiB
Python

#!/usr/bin/env python3
from time import time
def run_hanoi_algorithm(hanoi_function, num_disks, print_steps=False, print_stack=False):
stacks = get_starting_stack(num_disks)
if print_stack:
pretty_print_stacks(stacks)
hanoi_function(len(stacks["left"]), stacks, "left", "middle", "right", print_steps, print_stack)
def pretty_print_stacks(hanoi_stacks):
to_print = "Left:%s\tMiddle:%s\tRight:%s" % (hanoi_stacks["left"], hanoi_stacks["middle"], hanoi_stacks["right"])
print(to_print.expandtabs(40))
def get_starting_stack(num_start_disks):
stacks = {
"left": [i for i in range(1, num_start_disks + 1)],
"middle": [],
"right": []
}
return stacks
def move_disk(hanoi_stacks, starting_post, ending_post, print_steps=False, print_stack=False):
hanoi_stacks[ending_post].insert(0, hanoi_stacks[starting_post].pop(0))
if print_steps:
print("Moved disk from %s to %s" % (starting_post, ending_post))
if print_stack:
pretty_print_stacks(hanoi_stacks)
def hanoi_recursive(height, hanoi_stacks, starting_post, temp_post, ending_post, print_steps=False, print_stack=False):
if height > 0:
hanoi_recursive(height - 1, hanoi_stacks, starting_post, ending_post, temp_post, print_steps, print_stack)
move_disk(hanoi_stacks, starting_post, ending_post, print_steps, print_stack)
hanoi_recursive(height - 1, hanoi_stacks, temp_post, starting_post, ending_post, print_steps, print_stack)
def make_legal_move(height, hanoi_stacks, starting_post, ending_post, print_steps=False, print_stack=False):
if len(hanoi_stacks["right"]) == height or \
(len(hanoi_stacks[starting_post]) == 0 and len(hanoi_stacks[ending_post]) == 0):
return
elif len(hanoi_stacks[starting_post]) == 0:
larger = starting_post
smaller = ending_post
elif len(hanoi_stacks[ending_post]) == 0:
larger = ending_post
smaller = starting_post
else:
larger = starting_post if hanoi_stacks[starting_post][0] > hanoi_stacks[ending_post][0] else ending_post
smaller = starting_post if larger != starting_post else ending_post
move_disk(hanoi_stacks, smaller, larger, print_steps, print_stack)
def hanoi_iterative(height, hanoi_stacks, starting_post, temp_post, ending_post, print_steps=False, print_stack=False):
while len(hanoi_stacks["right"]) != height:
if height % 2 == 0:
make_legal_move(height, hanoi_stacks, starting_post, temp_post, print_steps, print_stack)
make_legal_move(height, hanoi_stacks, starting_post, ending_post, print_steps, print_stack)
else:
make_legal_move(height, hanoi_stacks, starting_post, ending_post, print_steps, print_stack)
make_legal_move(height, hanoi_stacks, starting_post, temp_post, print_steps, print_stack)
make_legal_move(height, hanoi_stacks, temp_post, ending_post, print_steps, print_stack)
if __name__ == "__main__":
# ##### Variables for Later #####
recursive_timings = [[], []]
iterative_timings = [[], []]
num_timing_iterations = 25
# ##### Problem 1 #####
print("CS 325 - Homework 2 - Corwin Perren")
print("\n\n########## Problem 1 ##########")
print("Recursive and iterative version of hanoi made...")
# Recursive and iterative version made. See the two immediate functions above.
# ##### Problem 2 #####
print("\n\n########## Problem 2 ##########")
# Recursive 3 disks
print("### Hanoi Recursive - 3 Disks - Printed Steps ###")
run_hanoi_algorithm(hanoi_recursive, 3, True, False)
# Recursive 4 disks
print("\n\n### Hanoi Recursive - 4 Disks - Printed Steps ###")
run_hanoi_algorithm(hanoi_recursive, 4, True, False)
# Iterative 3 disks
print("\n\n### Hanoi Iterative - 3 Disks - Printed Steps ###")
run_hanoi_algorithm(hanoi_iterative, 3, True, False)
# Iterative 4 disks
print("\n\n### Hanoi Iterative - 4 Disks - Printed Steps ###")
run_hanoi_algorithm(hanoi_iterative, 4, True, False)
# Verified that these are the correct steps
# ##### Problem 3 #####
print("\n\n########## Problem 3 ##########")
print("### 4 Disks - Print Out Successive Contents from Recursion ###")
run_hanoi_algorithm(hanoi_recursive, 4, False, True)
# ##### Problem 4 #####
print("\n\n########## Problem 4 ##########")
print("### Recursive Timings For Small n ###")
for current_n in range(1, num_timing_iterations):
start_time = time()
run_hanoi_algorithm(hanoi_recursive, current_n)
run_time = time() - start_time
recursive_timings[0].append(current_n)
recursive_timings[1].append(run_time)
print("%s disks: %.10f seconds" % (current_n, run_time))
print("### Iterative Timings For Small n ###")
for current_n in range(1, num_timing_iterations):
start_time = time()
run_hanoi_algorithm(hanoi_iterative, current_n)
run_time = time() - start_time
iterative_timings[0].append(current_n)
iterative_timings[1].append(run_time)
print("%s disks: %.10f seconds" % (current_n, run_time))
# ##### Problem 5 #####
print("\n\n########## Problem 5 ##########")
print("### Plots shown below, or printouts for spreadsheet if run from code ###")
for i in range(len(recursive_timings[0])):
print("%s\t%s" % (recursive_timings[0][i], recursive_timings[1][i]))
for i in range(len(iterative_timings[0])):
print("%s\t%s" % (iterative_timings[0][i], iterative_timings[1][i]))
# ##### Problem 6 #####
print("\n\n########## Problem 6 ##########")
print("Recursive C Value is approximately equal to 7.42E-07")
print("Iterative C Value is approximately equal to 1.13E-06")
# ##### Problem 7 #####
print("\n\n########## Problem 7 ##########")
print("The recursive algorithm will be faster for large n.")
# ##### Problem 8 #####
print("\n\n########## Problem 8 ##########")
print("The recursive algorithm would take approximately 434027 years for 64 disks.")
print("The iterative algorithm would take approximately 660985 years for 64 disks.")
# ##### Problem 9 #####
print("\n\n########## Problem 9 ##########")
print("The recursive algorithm could solve approximately 29 disks in ten minutes.")
print("The iterative algorithm could solve approximately 28 disks in ten minutes.")