Python/graphs/kahns_algorithm_long.py
Vysor df04d94543 Some directories had a capital in their name [fixed]. Added a recursive factorial algorithm. (#763)
* Renaming directories
* Adding a recursive factorial algorithm
2019-04-22 22:53:56 +08:00

31 lines
767 B
Python

# Finding longest distance in Directed Acyclic Graph using KahnsAlgorithm
def longestDistance(l):
indegree = [0] * len(l)
queue = []
longDist = [1] * len(l)
for key, values in l.items():
for i in values:
indegree[i] += 1
for i in range(len(indegree)):
if indegree[i] == 0:
queue.append(i)
while(queue):
vertex = queue.pop(0)
for x in l[vertex]:
indegree[x] -= 1
if longDist[vertex] + 1 > longDist[x]:
longDist[x] = longDist[vertex] + 1
if indegree[x] == 0:
queue.append(x)
print(max(longDist))
# Adjacency list of Graph
l = {0:[2,3,4], 1:[2,7], 2:[5], 3:[5,7], 4:[7], 5:[6], 6:[7], 7:[]}
longestDistance(l)