100.Same Tree
===

###### tags: `Easy`,`Tree`,`DFS`,`BFS`,`Binary Tree`

[100. Same Tree](https://leetcode.com/problems/same-tree/)

### 題目描述

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.

### 範例

**Example 1:**


Input: p = [1,2,3], q = [1,2,3]
Output: true

**Example 2:**


Input: p = [1,2], q = [1,null,2]
Output: false

**Example 3:**


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^

### 解答

#### Javascript

function isSameTree(p, q) {
  if (p === null && q === null) return true;
  if (p === null || q === null) return false;
  if (p.val !== q.val) return false;
  return isSameTree(p.left, q.left) && isSameTree(p.right, q.right);
}

> [name=Marsgoat] [time= Jan 10, 2023]

#### Python

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
        return p.val == q.val and self.isSameTree(p.left, q.left) and self.isSameTree(p.right, q.right)

> [name=Ron Chen][time=Tue, Jan 10, 2023]

分享討論區中發現的一行解法

def isSameTree(self, p, q):
    return p and q and p.val == q.val and all(map(self.isSameTree, (p.left, p.right), (q.left, q.right))) or p is q

#### c#

public class Solution {
    public bool IsSameTree(TreeNode p, TreeNode q) {
        if (p == null && q == null) return true;
        if (p == null || q == null) return false;
        if (p.val != q.val) return false;
        return IsSameTree(p.left, q.left) && IsSameTree(p.right, q.right);
    }
}

> [name=Jim][time=Tue, Jan 10, 2023]

### Reference

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