python code, please help me fix the error, when run the code, the code not stop and there is no graph after run the code

CODE

import numpy as np import copy import random import pandas as pd import time import matplotlib.pyplot as plt INF = 99999999 def random_graph(num_vertices, max_cost): cm = [[0]*num_vertices for i in range(num_vertices)] for i in range(num_vertices): for j in range(num_vertices): if i == j: cm[i][j] = INF else: cm[i][j] = random.randint(1, max_cost) return cm def init_dist(matrix): dist = copy.deepcopy(matrix) n = len(dist) for i in range(n): dist[i][i] = 0 return dist def to_table(matrix): n = len(matrix) table = [[] for i in range(n)] for i in range(n): for j in range(n): if matrix[i][j] < INF: table[i].append((j, matrix[i][j])) return table def get_edges(matrix): edges = [] n = len(matrix) for i in range(n): for j in range(n): cost = matrix[i][j] if cost < INF: edges.append((i, j, cost)) return edges def floyd_apsp(matrix): n = len(matrix) dist = init_dist(matrix) for k in range(n): for i in range(n): for j in range(n): dist[i][j] = min(dist[i][j], dist[i][k] + dist[k][j]) return dist def bellman_ford_apsp(matrix): edges = get_edges(matrix) n = len(matrix) dist = init_dist(matrix) for src in range(n): dist[src][src] = 0 for i in range(n - 1): for u, v, w in edges: if dist[src][u] + w < dist[src][v]: dist[src][v] = dist[src][u] + w for u, v, w in edges: if dist[src][u] + w < dist[src][v]: print("Graph contains negative weight cycle") return return dist def find_min(keys, used): mn = INF mn_idx = -1 for u in range(len(keys)): if keys[u] < mn and not used[u]: mn = keys[u] mn_idx = u return mn_idx def dijkstra_apsp(matrix): table = to_table(matrix) n = len(matrix) dist = init_dist(matrix) for src in range(n): dist[src][src] = 0 used = [False] * n for i in range(n): x = find_min(dist[src], used) used[x] = True for y in range(n): if not used[y] and dist[src][y] > dist[src][x] + matrix[x][y]: dist[src][y] = dist[src][x] + matrix[x][y] return dist def print_matrix(matrix): print(np.array(matrix)) print("") def print_table(table): n = len(table) for i in range(n): print(i, table[i]) def mini_test(): n = 10 matrix = random_graph(n, 99) print_matrix(matrix) table = to_table(matrix) print_table(table) dist = floyd_apsp(matrix) print("Floyd") print_matrix(dist) dist = bellman_ford_apsp(matrix) print("Bellman Ford") print_matrix(dist) dist = dijkstra_apsp(matrix) print("Dijkstra") print_matrix(dist) def run_algs(algs, sizes, trials): dict_algs = {} for alg in algs: dict_algs[alg.__name__] = {} for size in sizes: for alg in algs: dict_algs[alg.__name__][size] = 0 for trial in range(1, trials + 1): matrix = random_graph(size, 99) if size == sizes[0]: print("Matrix") print_matrix(matrix) for alg in algs: start_time = time.time() dist = alg(matrix) if size == sizes[0]: print(alg.__name__) print_matrix(dist) end_time = time.time() net_time = end_time - start_time dict_algs[alg.__name__][size] += 1000 * net_time return dict_algs def plot_times(dict_algs, sizes, trials, algs, title, file_name): alg_num = 0 plt.xticks([j for j in range(len(sizes))], [str(size) for size in sizes]) for alg in algs: alg_num += 1 d = dict_algs[alg.__name__] x_axis = [j + 0.05 * alg_num for j in range(len(sizes))] y_axis = [d[i] for i in sizes] plt.bar(x_axis, y_axis, width=0.05, alpha=0.75, label=alg.__name__) plt.legend() plt.title(title) plt.xlabel("Size") plt.ylabel("Time for " + str(trials) + " trials (ms)") plt.savefig(file_name) plt.show() def print_times(dict_algs): pd.set_option("display.max_rows", 500) pd.set_option("display.max_columns", 500) pd.set_option("display.width", 1000) df = pd.DataFrame.from_dict(dict_algs).T print(df) def main(): # mini_test() assn = "Assignment7" sizes = [10 * i for i in range(1, 11)] algs = [floyd_apsp, bellman_ford_apsp, dijkstra_apsp] trials = 10 title = "Runtime of APSP Algorithms" dict_algs = run_algs(algs, sizes, trials) print_times(dict_algs) plot_times(dict_algs, sizes, trials, algs, title, assn + ".png") if __name__ == "__main__": main()