mirror of
https://github.com/TheAlgorithms/Python.git
synced 2024-11-24 13:31:07 +00:00
32 lines
778 B
Python
32 lines
778 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)
|