Watch 10 video solutions for Find Duplicate Subtrees, a medium level problem involving Hash Table, Tree, Depth-First Search. This walkthrough by NeetCodeIO has 22,954 views views. Want to try solving it yourself? Practice on FleetCode or read the detailed text solution.
Given the root of a binary tree, return all duplicate subtrees.
For each kind of duplicate subtrees, you only need to return the root node of any one of them.
Two trees are duplicate if they have the same structure with the same node values.
Example 1:
Input: root = [1,2,3,4,null,2,4,null,null,4] Output: [[2,4],[4]]
Example 2:
Input: root = [2,1,1] Output: [[1]]
Example 3:
Input: root = [2,2,2,3,null,3,null] Output: [[2,3],[3]]
Constraints:
[1, 5000]-200 <= Node.val <= 200