IRCTC Station Tree Flatten to List
IRCTC Station Tree Flatten to List
MediumTrees0% accepted
IRCTC stores train route branches as a binary tree. For linear processing, engineers need to flatten the binary tree into a linked list in-place (right pointers form the chain, left pointers are all null, order is pre-order). Given the root of a binary tree, flatten it in-place and return the root.
Approach
Flatten a binary tree to a linked list in-place using pre-order traversal.
Input
6
1 2 5 3 4 -1 6
Output
1 2 3 4 5 6
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