/Python/Def Dijsktra(graph,source): dist = [0]*5 dist[0] = source v = 1 unvisited = {place: None for place in graph.keys()} visited = {} current = source currentDistance = 0 unvisited[current] = currentDistance

Def Dijsktra(graph,source): dist = [0]*5 dist[0] = source v = 1 unvisited = {place: None for place in graph.keys()} visited = {} current = source currentDistance = 0 unvisited[current] = currentDistance

nodes = ('A', 'B', 'C', 'D', 'E', 'F', 'G')
distances = {
    'B': {'A': 5, 'D': 1, 'G': 2},
    'A': {'B': 5, 'D': 3, 'E': 12, 'F' :5},
    'D': {'B': 1, 'G': 1, 'E': 1, 'A': 3},
    'G': {'B': 2, 'D': 1, 'C': 2},
    'C': {'G': 2, 'E': 1, 'F': 16},
    'E': {'A': 12, 'D': 1, 'C': 1, 'F': 2},
    'F': {'A': 5, 'E': 2, 'C': 16}}

unvisited = {node: None for node in nodes} #using None as +inf
visited = {}
current = 'B'
currentDistance = 0
unvisited[current] = currentDistance

while True:
    for neighbour, distance in distances[current].items():
        if neighbour not in unvisited: continue
        newDistance = currentDistance + distance
        if unvisited[neighbour] is None or unvisited[neighbour] > newDistance:
            unvisited[neighbour] = newDistance
    visited[current] = currentDistance
    del unvisited[current]
    if not unvisited: break
    candidates = [node for node in unvisited.items() if node[1]]
    current, currentDistance = sorted(candidates, key = lambda x: x[1])[0]

print(visited)

Source: stackoverflow.com

Similar codes

2 votes197 views2 answers
Check all python versions ubuntu
Python
0 vote216 views1 answer
Python intitialize a 2d matrix
Python
81 votes196 views6 answers
String to date python
Python
5 votes180 views4 answers
How to capture cmd output in python
Python
-1 vote242 views1 answer
Install grepper for edge
Python
0 vote210 views1 answer
If function has no argument python
Python
0 vote236 views1 answer
Pytest check exception
Python
69 votes229 views4 answers
Python csv dictwriter
Python
4 votes185 views1 answer
Python dictionary add key-value pair
Python
3 votes230 views1 answer
Python get output of command to variable
Python