652. Find Duplicate Subtrees

LeetCodeHash TableTreeDepth-First SearchBinary TreeOpen on judge ↗

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 =

HINT LADDERno hints yet

L1 Observation

L2 Technique

L3 Approach

L4 Pseudo-code

🔒

L5 Full solution

L5 unlocks only if you insist twice

solution.cppC++17

CodeSearch Tutor

Hints, not spoilers — it won’t hand over the full solution unless you insist.

voice by Sarvam AI