---
# System prepended metadata

title: LeetCode 100.Same Tree
tags: [Tree, Depth-First Search, Breasth-First Search, Binary Tree]

---

###### tags: `Tree`, `Depth-First Search`, `Breasth-First Search`, `Binary Tree`

# LeetCode 100.Same Tree
Given the roots of two binary trees ```p``` and ```q```, 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:

![image alt](https://assets.leetcode.com/uploads/2020/12/20/ex1.jpg)
```
Input: p = [1,2,3], q = [1,2,3]
Output: true
```
>Example 2:

![image alt](https://assets.leetcode.com/uploads/2020/12/20/ex2.jpg)
```
Input: p = [1,2], q = [1,null,2]
Output: false
```
>Example 3:

![image alt](https://assets.leetcode.com/uploads/2020/12/20/ex3.jpg)
```
Input: p = [1,2,1], q = [1,1,2]
Output: false
```
 

### Constraints:

- The number of nodes in both trees is in the range ```[0, 100]```.
- $-10^4 <= Node.val <= 10^4$
---
### Idea:
>利用遞回的方式去判斷兩棵樹相同節點，有沒有一樣。
### Solution

Python:
```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 isSameTree(self, p: Optional[TreeNode], q: Optional[TreeNode]) -> bool:
        if not p and not q :
            return True
        if not p or not q:
            return False
        if p.val != q.val:
            return False
        return self.isSameTree(p.left,q.left) and self.isSameTree(p.right,q.right) 
```

C++:
```cpp=
```
