Flatten Binary Tree to Linked List II
Another problem where you either have to flatten the binary tree into a linked list, or push it into a queue. I decided to do the former - it is easy to have a list of list of nodes, where each index is the level of the tree, and each list is the list of nodes in that level. If you do a pre-order depth-first search (DFS) you can accomplish that. Second part of the problem is the calculation based on the given rules. Just go thru the flatten list, and to the list of nodes, and process based on the rules. If you look at the code down below, it achieves a high degree of symmetry which is usually a trademark when operating with trees. Cheers, ACC. Zigzag Level Sum of Binary Tree - LeetCode You are given the root of a binary tree . Traverse the tree level by level using a zigzag pattern: At odd -numbered levels (1-indexed), traverse nodes from left to right . At even -numbered levels, traverse nodes from right to left . While traversing a level in th...
