Solution: Flatten Binary Tree to Linked List
Explore how to transform a binary tree into a linked list by applying an optimized depth-first search approach. Understand how to rearrange nodes in preorder traversal order without extra space, and apply this technique to efficiently solve tree-related coding interview questions.
Statement
Given the root of a binary tree, the task is to flatten the tree into a linked list using the same TreeNode class. The left child pointer of each node in the linked list should always be NULL, and the right child pointer should point to the next node in the linked list. The nodes in the linked list should be in the same order as that of the preorder traversal of the given binary tree.
Constraints: