algorithm-in-python/graph/isBipartGraph.py

34 lines
1.0 KiB
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]