python3

javascript

java

Symmetric Tree

Given the `root` of a binary tree, check whether it is a mirror of itself (i.e., symmetric around its center).

```
Class TreeNode:
    val (int)
    left (TreeNode)
    right (TreeNode)
```

### Input Format

First Parameter - TreeNode `root`

### Output Format

Return the number.


### Example 1:
```
Input: 1 2 2 3 4 4 3
Output: 1
```
!["1"](https://devsnest-custom-images.s3.ap-south-1.amazonaws.com/symtree1)
### Example 2:
```
Input: 1 2 2 null 3 null 3
Output: 0
```
!["1"](https://devsnest-custom-images.s3.ap-south-1.amazonaws.com/symtree2)

#### Constraints:
+ The number of nodes in the tree is in the range `[1, 1000]`.
+ -100 <= `Node.val` <= 100
+ Expected Time Complexity: O(n)
+ Expected Space Complexity: O(n)

int solve(TreeNode* root){
//CODE HERE 
}

static int solve(TreeNode root){
//CODE HERE 
}