Data Structures & Algorithms Graphs

from collections import deque graph = dict() graph['A'] = ['B', 'G', 'D'] graph['B'] = ['A', 'F', 'E'] graph['C'] = ['F', 'H'] graph['D'] = ['F', 'A'] graph['E'] = ['B', 'G'] graph['F'] = ['B', 'D', 'C'] graph['G'] = ['A', 'E'] graph['H'] = ['C'] def breadth_first_search(graph, root): visited_vertices = list() graph_queue = deque([root]) visited_vertices.append(root) node = root while len(graph_queue) > 0: node = graph_queue.popleft() adj_nodes = graph[node] remaining_elements = set(adj_nodes).difference(set(visited_vertices)) if len(remaining_elements) > 0: for elem in sorted(remaining_elements): visited_vertices.append(elem) graph_queue.append(elem) return visited_vertices print(breadth_first_search(graph, 'A'))