872. Leaf-Similar Trees-叶子相似的树

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.

Example 1:

Input: root1 = [3,5,1,6,2,9,8,null,null,7,4], root2 = [3,5,1,6,7,4,2,null,null,null,null,null,null,9,8]
Output: true

Example 2:
Input: root1 = [1], root2 = [1]
Output: true

Example 3:
Input: root1 = [1], root2 = [2]
Output: false

Example 4:
Input: root1 = [1,2], root2 = [2,2]
Output: true

Example 5:

Input: root1 = [1,2,3], root2 = [1,3,2]
Output: false

Constraints:

• The number of nodes in each tree will be in the range [1, 200].
• Both of the given trees will have values in the range [0, 200].

Solution in python:

# Definition for a binary tree node.
# class TreeNode:
#     def __init__(self, val=0, left=None, right=None):
#         self.val = val
#         self.left = left
#         self.right = right
class Solution:
    def leafSimilar(self, root1: TreeNode, root2: TreeNode) -> bool:
        def traverse(root):
            if root == None:
                return []
            else:
                temp = []
                left_lis = traverse(root.left)
                right_lis = traverse(root.right)
                temp.extend(left_lis)
                temp.extend(right_lis)
                if (not root.left) and (not root.right):
                    temp.append(root.val)
                return temp

        alist = traverse(root1)
        blist = traverse(root2)
        if len(alist) != len(blist):
            return False
        else:
            for i in range(len(alist)):
                if alist[i] != blist[i]:
                    return False
        return True