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Binary Tree Structural Check
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Binary Tree Structural Check

MediumPython

Problem

Algorithm question: determine whether binary tree B is a substructure of binary tree A. Describe your approach first, then implement it.

Asked in the round 1 coding stage.

Input and Output

Represent each tree as [value, left, right], where a missing child is null. Implement is_substructure(a, b) and return true if B matches a connected pattern in A. A pattern may end before A does, but every node in B must match in value and position. An empty B is not a substructure.

Constraints

  • Each tree contains at most 1000 nodes.
  • Node values are integers in the range -10^9 to 10^9.
  • Either input tree may be null.
  • An empty B is not a valid substructure.

Function Signature

def is_substructure(a, b):
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