---
tags: leetcode
---

# [100. Same Tree](https://leetcode.com/problems/same-tree/)
---
# My Solution
## The Key Idea for Solving This Coding Question
## C++ Code

/**
 * Definition for a binary tree node.
 * struct TreeNode {
 *     int val;
 *     TreeNode *left;
 *     TreeNode *right;
 *     TreeNode() : val(0), left(nullptr), right(nullptr) {}
 *     TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
 *     TreeNode(int x, TreeNode *left, TreeNode *right) : val(x), left(left), right(right) {}
 * };
 */

class Solution {
public:
    bool isSameTree(TreeNode *p, TreeNode *q) {
        if (p == nullptr && q == nullptr) {
            return true;
        }

        if (p == nullptr || q == nullptr) {
            return false;
        }

        if (p->val != q->val) {
            return false;
        }

        return isSameTree(p->left, q->left) && isSameTree(p->right, q->right);
    }
};

## Time Complexity
$O(n)$
$n$ is the number of nodes in the binary tree.
## Space Complexity
$O(H)$
$H$ is the height of the binary tree.
# Miscellane
<!--
# Test Cases

[1,2,3]
[1,2,3]

[1,2]
[1,null,2]

[1,2,1]
[1,1,2]

[0,-5]
[0,-8]

[10,5,15]
[10,5,null,null,15]

[1,1]
[1,null,1]

[]
[0]

-->