Same Tree——Depth-first Search

Given two binary trees, write a function to check if they are equal or not.

Two binary trees are considered equal if they are structurally identical and the nodes have the same value.

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

class Solution(object):
    L = []
    R = []
    def getLChilds(self, root):
        if not root:
            self.L.append('#')
            return

        self.L.append(root.val)
        self.getLChilds(root.right)
        self.getLChilds(root.left)
    
    def getRChilds(self, root):
        if not root:
            self.R.append('#')
            return

        self.R.append(root.val)
        self.getRChilds(root.right)
        self.getRChilds(root.left)
        
    def isSameTree(self, p, q):
        """
        :type p: TreeNode
        :type q: TreeNode
        :rtype: bool
        """
        self.L = []
        self.R = []
        if not p and not q: return True
        if not p and q: return False
        if p and not q: return False
        self.getLChilds(p)
        self.getRChilds(q)
        if self.L == self.R: 
            return True
        else:
            return False