Watch 10 video solutions for N-ary Tree Postorder Traversal, a easy level problem involving Stack, Tree, Depth-First Search. This walkthrough by Nick White has 51,096 views views. Want to try solving it yourself? Practice on FleetCode or read the detailed text solution.
Given the root of an n-ary tree, return the postorder traversal of its nodes' values.
Nary-Tree input serialization is represented in their level order traversal. Each group of children is separated by the null value (See examples)
Example 1:
Input: root = [1,null,3,2,4,null,5,6] Output: [5,6,3,2,4,1]
Example 2:
Input: root = [1,null,2,3,4,5,null,null,6,7,null,8,null,9,10,null,null,11,null,12,null,13,null,null,14] Output: [2,6,14,11,7,3,12,8,4,13,9,10,5,1]
Constraints:
[0, 104].0 <= Node.val <= 1041000.
Follow up: Recursive solution is trivial, could you do it iteratively?