LC-0617 Easy LeetCode

617. Merge Two Binary Trees

Tree Depth-First Search Breadth-First Search Binary Tree

Read the full problem statement on LeetCode.

Difficulty: easy Acceptance: 79% Topics: Tree, Depth-First Search, Breadth-First Search, Binary Tree

Reading material

Reference solution (spoiler · python)

# Time:  O(n)
# Space: O(h)

class Solution(object):
    def mergeTrees(self, t1, t2):
        """
        :type t1: TreeNode
        :type t2: TreeNode
        :rtype: TreeNode
        """
        if t1 is None:
            return t2
        if t2 is None:
            return t1
        t1.val += t2.val
        t1.left = self.mergeTrees(t1.left, t2.left)
        t1.right = self.mergeTrees(t1.right, t2.right)
        return t1

Solution from kamyu104/LeetCode-Solutions · MIT