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Cycle-Free Network Path Validation
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Cycle-Free Network Path Validation

MediumPython

Problem

Implement a function to determine whether a given network path between nodes is valid and avoid cycles in the traversal. Use a directed graph represented as an adjacency-list dictionary, a starting node, and a destination node. Return True if the destination is reachable without visiting any node more than once; otherwise return False.

Function signature: def is_valid_path(graph, start, target):

Constraints

  • The graph is a directed adjacency-list dictionary.
  • Node identifiers are hashable values.
  • 0 <= number of nodes <= 500.
  • Each adjacency list contains zero or more node identifiers.
  • A node may appear as a neighbor without having its own dictionary entry.

Function Signature

def is_valid_path(graph, start, target):
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