# Symmetric Tree – Leetcode Solution

In this post, we are going to solve the 101. Symmetric Tree problem of Leetcode. This problem 101. Symmetric Tree is a Leetcode easy level problem. Let’s see the code, 101. Symmetric Tree – Leetcode Solution.

## Problem

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

### Example 1 :

``````Input: root = [1,2,2,3,4,4,3]
Output: true``````

### Example 2 :

``````Input: root = [1,2,2,null,3,null,3]
Output: false``````

### Constraints

• The number of nodes in the tree is in the range `[1, 1000]`.
• `-100 <= Node.val <= 100`

Now, let’s see the code of 101. Symmetric Tree – Leetcode Solution.

# Symmetric Tree – Leetcode Solution

### 101. Symmetric Tree – Solution in Java

```/**
* Definition for a binary tree node.
* public class TreeNode {
*     int val;
*     TreeNode left;
*     TreeNode right;
*     TreeNode() {}
*     TreeNode(int val) { this.val = val; }
*     TreeNode(int val, TreeNode left, TreeNode right) {
*         this.val = val;
*         this.left = left;
*         this.right = right;
*     }
* }
*/
class Solution {

public boolean isSymmetricRec(TreeNode left, TreeNode right){

if(left == null || right == null){
return left == right;
}
if(left.val != right.val) return false;

return isSymmetricRec(left.left,right.right) && isSymmetricRec(right.left,left.right);

}

public boolean isSymmetric(TreeNode root) {
return root == null || isSymmetricRec(root.left,root.right);
}
}```

### 101. Symmetric Tree – Solution in C++

```/**
* 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 isSymmetric(TreeNode* root) {

if(root==NULL) return true;

return isSymmetricTest(root->left,root->right);
}

bool isSymmetricTest(TreeNode* p , TreeNode* q){
if(p == NULL && q == NULL)
return true;

else if(p == NULL || q == NULL)
return false;

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

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

### 101. Symmetric Tree– Solution in Python

```# Definition for a binary tree node.
# class TreeNode(object):
#     def __init__(self, val=0, left=None, right=None):
#         self.val = val
#         self.left = left
#         self.right = right
class Solution(object):
def isSymmetric(self, root):
if not root:
return True
return self.dfs(root.left, root.right)

def dfs(self, l, r):
if l and r:
return l.val == r.val and self.dfs(l.left, r.right) and self.dfs(l.right, r.left)
return l == r
```

Note: This problem 101. Symmetric Tree is generated by Leetcode but the solution is provided by CodingBroz. This tutorial is only for Educational and Learning purpose.