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1 changed files with 56 additions and 16 deletions

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@ -1,6 +1,8 @@
from preprocessing import parse_file from preprocessing import parse_file
from pandas import DataFrame from pandas import DataFrame, Series
from sys import argv from sys import argv
from random import seed, randint
from time import time
def get_first_solution(n, data): def get_first_solution(n, data):
@ -11,7 +13,7 @@ def get_first_solution(n, data):
distance_sum = distance_sum.append( distance_sum = distance_sum.append(
{"point": element, "distance": distance}, ignore_index=True {"point": element, "distance": distance}, ignore_index=True
) )
furthest_index = distance_sum["distance"].idxmax() furthest_index = distance_sum["distance"].astype(float).idxmax()
furthest_row = distance_sum.iloc[furthest_index] furthest_row = distance_sum.iloc[furthest_index]
furthest_row["distance"] = 0 furthest_row["distance"] = 0
return furthest_row return furthest_row
@ -25,11 +27,14 @@ def get_different_element(original, row):
def get_furthest_element(element, data): def get_furthest_element(element, data):
element_df = data.query(f"source == {element} or destination == {element}") element_df = data.query(f"source == {element} or destination == {element}")
furthest_index = element_df["distance"].idxmax() furthest_index = element_df["distance"].astype(float).idxmax()
furthest_row = data.iloc[furthest_index] furthest_row = data.iloc[furthest_index]
furthest_point = get_different_element(original=element, row=furthest_row) furthest_point = get_different_element(original=element, row=furthest_row)
furthest_element = {"point": furthest_point, "distance": furthest_row["distance"]} return Series(data={"point": furthest_point, "distance": furthest_row["distance"]})
return furthest_element, furthest_index
def remove_solution_dataset(data, solution):
return data.query(f"source != {solution} and destination != {solution}")
def greedy_algorithm(n, m, data): def greedy_algorithm(n, m, data):
@ -37,29 +42,64 @@ def greedy_algorithm(n, m, data):
first_solution = get_first_solution(n, data) first_solution = get_first_solution(n, data)
solutions = solutions.append(first_solution, ignore_index=True) solutions = solutions.append(first_solution, ignore_index=True)
for _ in range(m): for _ in range(m):
last_solution = solutions["point"].tail(n=1) last_solution = int(solutions["point"].tail(n=1))
centroid, index = get_furthest_element(element=int(last_solution), data=data) centroid = get_furthest_element(element=last_solution, data=data)
solutions = solutions.append(dict(centroid), ignore_index=True) solutions = solutions.append(centroid, ignore_index=True)
data = data.drop(index) data = remove_solution_dataset(data=data, solution=last_solution)
return solutions return solutions
# NOTE In each step, switch to the element that gives the least amount def get_pseudorandom_solution(n, data):
def local_search(): seed(42)
solution = data.iloc[randint(a=0, b=n)]
return Series(data={"point": solution["destination"], "distance": 0})
def local_search(n, m, data):
solutions = DataFrame(columns=["point", "distance"])
first_solution = get_pseudorandom_solution(n=n, data=data)
solutions = solutions.append(first_solution, ignore_index=True)
for _ in range(m):
pass pass
return solutions
def execute_algorithm(choice, n, m, data):
if choice == "greedy":
return greedy_algorithm(n, m, data)
elif choice == "local":
return local_search(n, m, data)
else:
print("The valid algorithm choices are 'greedy' and 'local'")
exit(1)
def show_results(solutions, time_delta):
distance_sum = solutions["distance"].sum()
duplicates = solutions.duplicated()
print(solutions)
print("Total distance: " + str(distance_sum))
if solutions[duplicates].empty:
print("No duplicates found")
print("Execution time: " + str(time_delta))
def usage(argv): def usage(argv):
print(f"Usage: python {argv[0]} <file>") print(f"Usage: python {argv[0]} <file> <algorithm choice>")
print("algorithm choices:")
print("greedy: greedy algorithm")
print("local: local search algorithm")
exit(1) exit(1)
def main(): def main():
if len(argv) != 2: if len(argv) != 3:
usage(argv) usage(argv)
n, m, data = parse_file(argv[1]) n, m, data = parse_file(argv[1])
solutions = greedy_algorithm(n, m, data) start_time = time()
print(solutions) solutions = execute_algorithm(choice=argv[2], n=n, m=m, data=data)
end_time = time()
show_results(solutions, time_delta=end_time - start_time)
if __name__ == "__main__": if __name__ == "__main__":