Solution: Flatten Binary Tree to Linked List
Explore how to flatten a binary tree into a linked list by rearranging nodes in preorder traversal order. Learn to apply depth-first search recursively to transform the tree in place, optimizing space usage. Gain practical insights into linking subtrees and pointers without extra data structures, and understand the time and space complexity of the solution.
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: