题解 | #合并二叉树#

# class TreeNode:
#     def __init__(self, x):
#         self.val = x
#         self.left = None
#         self.right = None

#
# 
# @param t1 TreeNode类 
# @param t2 TreeNode类 
# @return TreeNode类
#
class Solution:
    def mergeTrees(self , t1 , t2 ):
        # write code here
        if not t1 :
            return t2
        if not t2:
            return t1
        t1.val = t1.val + t2.val
        left = self.mergeTrees(t1.left, t2.left)
        right = self.mergeTrees(t1.right, t2.right)
        t1.left = left
        t1.right = right
        return t1