Python/graphs/check_bipartite_graph_dfs.py
2019-05-16 19:24:56 +08:00

34 lines
987 B
Python

# Check whether Graph is Bipartite or Not using DFS
# A Bipartite Graph is a graph whose vertices can be divided into two independent sets,
# U and V such that every edge (u, v) either connects a vertex from U to V or a vertex
# from V to U. In other words, for every edge (u, v), either u belongs to U and v to V,
# or u belongs to V and v to U. We can also say that there is no edge that connects
# vertices of same set.
def check_bipartite_dfs(l):
visited = [False] * len(l)
color = [-1] * len(l)
def dfs(v, c):
visited[v] = True
color[v] = c
for u in l[v]:
if not visited[u]:
dfs(u, 1 - c)
for i in range(len(l)):
if not visited[i]:
dfs(i, 0)
for i in range(len(l)):
for j in l[i]:
if color[i] == color[j]:
return False
return True
# Adjacency list of graph
l = {0:[1,3], 1:[0,2], 2:[1,3], 3:[0,2], 4: []}
print(check_bipartite_dfs(l))