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

## 题目


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

```

## 题目大意

这一题要求判断 2 颗树是否是完全相等的。


## 解题思路

递归判断即可。




## 代码

```go

package leetcode

/**
 * Definition for a binary tree node.
 * type TreeNode struct {
 *     Val int
 *     Left *TreeNode
 *     Right *TreeNode
 * }
 */
func isSameTree(p *TreeNode, q *TreeNode) bool {
	if p == nil && q == nil {
		return true
	} else if p != nil && q != nil {
		if p.Val != q.Val {
			return false
		}
		return isSameTree(p.Left, q.Left) && isSameTree(p.Right, q.Right)
	} else {
		return false
	}
}

```