algorithm-in-python/graph/isBipartGraph.py
2019-01-31 12:09:46 +08:00

31 lines
1014 B
Python

#coding: utf-8
''' mbinary
#######################################################################
# File : isBipartGraph.py
# Author: mbinary
# Mail: zhuheqin1@gmail.com
# Blog: https://mbinary.xyz
# Github: https://github.com/mbinary
# Created Time: 2018-12-21 15:00
# Description: Judge if a graph is bipartite
The theorical idea is to judge whether the graph has a odd-path circle. However, it's hard to implement.
The following codes show a method that colors the nodes by dfs.
#######################################################################
'''
def isBipartite(self, graph):
"""
:type graph: List[List[int]]
:rtype: bool
"""
n = len(graph)
self.node = graph
self.color = {i:None for i in range(n)}
return all(self.dfs(i,True) for i in range(n) if self.color[i] is None)
def dfs(self,n,col=True):
if self.color[n] is None:
self.color[n]=col
return all(self.dfs(i,not col) for i in self.node[n])
else:return col==self.color[n]