LeetCode | 0100. Same Tree 相同的树【Python】

阳光穿透心脏的1/2处 2023-02-20 15:57 74阅读 0赞

> LeetCode 0100. Same Tree 相同的树【Easy】【Python】【二叉树】

### Problem ###

[LeetCode][]

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

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

**Example 1:**

Input:     1         1
              / \       / \
             2   3     2   3
    
            [1,2,3],   [1,2,3]
    
    Output: true

**Example 2:**

Input:     1         1
              /           \
             2             2
    
            [1,2],     [1,null,2]
    
    Output: false

**Example 3:**

Input:     1         1
              / \       / \
             2   1     1   2
    
            [1,2,1],   [1,1,2]
    
    Output: false

### 问题 ###

[力扣][Link 1]

给定两个二叉树，编写一个函数来检验它们是否相同。

如果两个树在结构上相同，并且节点具有相同的值，则认为它们是相同的。

**示例 1:**

输入:       1         1
              / \       / \
             2   3     2   3
            [1,2,3],   [1,2,3]
    输出: true

**示例 2:**

输入:      1          1
              /           \
             2             2
            [1,2],     [1,null,2]
    输出: false

**示例 3:**

输入:       1         1
              / \       / \
             2   1     1   2
            [1,2,1],   [1,1,2]
    输出: false

### 思路 ###

**二叉树**

##### Python3代码 #####

# Definition for a binary tree node.
    # class TreeNode:
    # def __init__(self, x):
    # self.val = x
    # self.left = None
    # self.right = None
    
    class Solution:
        def isSameTree(self, p: TreeNode, q: TreeNode) -> bool:
            # 两棵树都为空
            if not p and not q:
                return True
            # 一棵树为空，另一棵不为空
            elif not p or not q:
                return False
            # 两棵树都非空，但节点值不同
            elif p.val != q.val:
                return False
            # 分别判断左子树和右子树
            return self.isSameTree(p.left, q.left) and self.isSameTree(p.right, q.right)

### GitHub链接 ###

[Python][]

[LeetCode]: https://leetcode.com/problems/same-tree/
[Link 1]: https://leetcode-cn.com/problems/same-tree/
[Python]: https://github.com/Wonz5130/LeetCode-Solutions/blob/master/solutions/0100-Same-Tree/0100.py