Learn Algorithm Design by Building a Shortest Path Algorithm - Step 49

Python
1

Tell us what’s happening:

I feel like im creating a variable for target_to_print but its not accepting it. Please let me know what im doing wrong

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, target = ''):
    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)
    
    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:
                    paths[node] = paths[current][:]
                else:
                    paths[node].extend(paths[current])
                paths[node].append(node)
        unvisited.remove(current)

# User Editable Region

    targets_to_print if target else my_graph

shortest_path(my_graph, 'A')

# User Editable Region

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Challenge Information:

Learn Algorithm Design by Building a Shortest Path Algorithm - Step 49

2

This way you’re not creating a variable. The example in the instructions

val_1 if condition else val_2

represents just an expression you can assign to a variable:

variable_name = val_1 if condition else val_2
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