Convert binary tree traversals to forest count
Problem Description
Given the inorder and postorder traversals of a binary tree:
- Inorder:
A, B, C, D, E, F, G - Postorder:
B, D, C, A, F, G, E
This binary tree is then converted into an equivalent forest using the standard left-child/right-sibling representation. In this representation, the left child of a node in the original binary tree becomes the first child in the forest, and the right child becomes the next sibling.
The task is to determine the number of trees present in the resulting forest.
AI interview prep
Core dilemma
The central engineering conflict lies in accurately applying the left-child/right-sibling transformation rules to a reconstructed binary tree and correctly inferring the number of resulting trees in the forest, which often trips candidates who expect multiple roots. The true insight is that the original binary tree's root becomes the *only* root of a tree in the forest.
2 tradeoffs and 3 stress tests locked
Interview prep
Unlock the interviewer X-Ray rubric, tradeoff matrix, stress tests, clarifying questions, and key concepts.
Convert binary tree traversals to forest count
Problem Description
Given the inorder and postorder traversals of a binary tree:
- Inorder:
A, B, C, D, E, F, G - Postorder:
B, D, C, A, F, G, E
This binary tree is then converted into an equivalent forest using the standard left-child/right-sibling representation. In this representation, the left child of a node in the original binary tree becomes the first child in the forest, and the right child becomes the next sibling.
The task is to determine the number of trees present in the resulting forest.