DFS_BFS

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#!/usr/bin/env python # -*- coding: utf-8 -*- # @Time : 2019/11/17 10:28 # @Author : caius # @Site : # @File : BFS.py # @Software: PyCharm graph = { "A":{"B", "C"}, "B":{"A","C","D"}, "C":{"A","B","D","E"}, "D":{"B","C","E","F"}, "E":{"C","D"}, "F":{"D"} } # 字典的基本用法 # keys: A B C D E F # graph["E"} "c". "D" def BFS(graph, s): # 队列先进先出 queue=[] queue.append(s) seen = set()# 代表这个东西是个set seen.add(s) parrent ={} parrent={s:None} while(len(queue)>0): vertex = queue.pop(0) nodes = graph[vertex] for w in nodes: if w not in seen: queue.append(w) seen.add(w) parrent[w] = vertex print(vertex) return parrent def DFS(graph, s): # 队列先进先出 stack=[] stack.append(s) seen = set()# 代表这个东西是个set seen.add(s) while(len(stack)>0): vertex = stack.pop() nodes = graph[vertex] for w in nodes: if w not in seen: stack.append(w) seen.add(w) print(vertex) DFS(graph,"E") parrent = BFS(graph,'E') for key in parrent: print(key,parrent[key]) v = "B" count=-1 while v!= None: print(v) v = parrent[v] count+=1 print("count: {} 次".format(count))