题目描述

Given two binary trees and imagine that when you put one of them to cover the other, some nodes of the two trees are overlapped while the others are not.

Example 1:
Input: 
    Tree 1                     Tree 2                  
          1                         2                             
         / \                       / \                            
        3   2                     1   3                        
       /                           \   \                      
      5                             4   7                  
Output: 
Merged tree:
         3
        / \        4   5
      / \   \ 
     5   4   7

Note: The merging process must start from the root nodes of both trees.

python代码

class Solution:
    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=t1.val+t2.val
        t1.left = self.mergeTrees(t1.left,t2.left)
        t1.right = self.mergeTrees(t1.right,t2.right)
        return t1

此题看到感觉很容易,但对树的属性不是很熟,不知道怎么调用,代码是借鉴别人的.水平很渣,加油啊!