Watch 10 video solutions for Merge Two Binary Trees, a easy level problem involving Tree, Depth-First Search, Breadth-First Search. This walkthrough by NeetCode has 61,579 views views. Want to try solving it yourself? Practice on FleetCode or read the detailed text solution.
You are given two binary trees root1 and root2.
Imagine that when you put one of them to cover the other, some nodes of the two trees are overlapped while the others are not. You need to merge the two trees into a new binary tree. The merge rule is that if two nodes overlap, then sum node values up as the new value of the merged node. Otherwise, the NOT null node will be used as the node of the new tree.
Return the merged tree.
Note: The merging process must start from the root nodes of both trees.
Example 1:
Input: root1 = [1,3,2,5], root2 = [2,1,3,null,4,null,7] Output: [3,4,5,5,4,null,7]
Example 2:
Input: root1 = [1], root2 = [1,2] Output: [2,2]
Constraints:
[0, 2000].-104 <= Node.val <= 104