[LeetCode&Python] Problem 872. Leaf-Similar Trees

Consider all the leaves of a binary tree.  From left to right order, the values of those leaves form a leaf value sequence.

For example, in the given tree above, the leaf value sequence is (6, 7, 4, 9, 8).

Two binary trees are considered leaf-similar if their leaf value sequence is the same.

Return true if and only if the two given trees with head nodes root1 and root2 are leaf-similar.

Note:

• Both of the given trees will have between 1 and 100 nodes.

# Definition for a binary tree node.
# class TreeNode:
#     def __init__(self, x):
#         self.val = x
#         self.left = None
#         self.right = None

class Solution:
    def leafSimilar(self, root1, root2):
        """
        :type root1: TreeNode
        :type root2: TreeNode
        :rtype: bool
        """
        leaf=[]
        
        def findleaf(r):
            if not r.left and not r.right:
                leaf.append(r.val)
            elif not r.left and r.right!=None:
                findleaf(r.right)
            elif not r.right and r.left!=None:
                findleaf(r.left)
            else:
                findleaf(r.left)
                findleaf(r.right)
        
        findleaf(root1)
        leaf1=leaf
        leaf=[]
        findleaf(root2)
        
        if leaf==leaf1:
            return True
        return False