tvl-depot/users/wpcarro/scratch/facebook/mesh-message.py
Vincent Ambo 019f8fd211 subtree(users/wpcarro): docking briefcase at '24f5a642'
git-subtree-dir: users/wpcarro
git-subtree-mainline: 464bbcb15c
git-subtree-split: 24f5a642af
Change-Id: I6105b3762b79126b3488359c95978cadb3efa789
2021-12-14 02:15:47 +03:00

40 lines
1.2 KiB
Python

from heapq import heappush, heappop
import random
def shortest_path(a, b, graph):
seen = set()
h = []
heappush(h, (0, a, [a]))
while h:
km, x, path = heappop(h)
if x == b:
return path
for c in graph[x]:
if c not in seen:
heappush(h, (km + 1, c, path + [c]))
raise Exception("We were unable to find a path from {} to {}".format(a, b))
graph = {
'Min' : ['William', 'Jayden', 'Omar'],
'William' : ['Min', 'Noam'],
'Jayden' : ['Min', 'Amelia', 'Ren', 'Noam'],
'Ren' : ['Jayden', 'Omar'],
'Amelia' : ['Jayden', 'Adam', 'Miguel'],
'Adam' : ['Amelia', 'Miguel', 'Sofia', 'Lucas'],
'Miguel' : ['Amelia', 'Adam', 'Liam', 'Nathan'],
'Noam' : ['Nathan', 'Jayden', 'William'],
'Omar' : ['Ren', 'Min', 'Scott'],
'Liam' : ['Ren'],
'Nathan' : ['Noam'],
'Scott' : [],
}
result = shortest_path('Jayden', 'Adam', graph)
print(result)
assert result == ['Jayden', 'Amelia', 'Adam']
print('Success!')
beg = random.choice(list(graph.keys()))
end = random.choice(list(graph.keys()))
print("Attempting to find the shortest path between {} and {}".format(beg, end))
print(shortest_path(beg, end, graph))