diff --git a/10 October LeetCode Challenge 2021/26_invertBT.cpp b/10 October LeetCode Challenge 2021/26_invertBT.cpp
new file mode 100644
index 0000000..0ad73f3
--- /dev/null
+++ b/10 October LeetCode Challenge 2021/26_invertBT.cpp	
@@ -0,0 +1,25 @@
+/**
+ * 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:
+    TreeNode* invertTree(TreeNode* root) {
+        
+        if (root == NULL)   return root;
+        TreeNode* lt = invertTree(root->right);
+        TreeNode* rt = invertTree(root->left);
+        
+        root->left =lt;
+        root->right = rt;
+        
+        return root;
+    }
+};