Learn Algorithm Design by Building a Shortest Path Algorithm - Step 45

Python
1

Tell us what’s happening:

I am very frustrated on this step no idea where to begin on the reasoning behind why the code wont go through seen numerous posts which explained very little about WHY it wont work. I get this message every time. You should create a nested if statements that checks if paths[node][-1] is equal to node . Don’t forget to use pass .

Your code so far

my_graph = {
    'A': [('B', 3), ('D', 1)],
    'B': [('A', 3), ('C', 4)],
    'C': [('B', 4), ('D', 7)],
    'D': [('A', 1), ('C', 7)]
}

def shortest_path(graph, start):
    unvisited = list(graph)
    distances = {node: 0 if node == start else float('inf') for node in graph}
    paths = {node: [] for node in graph}
    paths[start].append(start)

# User Editable Region

    while unvisited:
        current = min(unvisited, key=distances.get)
        for node, distance in graph[current]:
            if distance + distances[current] < distances[node]:
                distances[node] = distance + distances[current]
                if paths[node] !=[] and paths[node][-1] == node:
                   pass
                 

# User Editable Region

    print(f'Unvisited: {unvisited}\nDistances: {distances}\nPaths: {paths}')
    
#shortest_path(my_graph, 'A')

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Challenge Information:

Learn Algorithm Design by Building a Shortest Path Algorithm - Step 45

2

The hint and the instructions only ask to check 1 thing, but you are checking 2 conditions with your if statement using and

3

So I would write only one of the two conditions ending with ==?

4

I just figured it out you were partially correct about using only one of the two conditions the other problem I encountered was with the second requirement, I had the wrong indentation.

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