Maximum Depth of Binary Tree solution

Author: kimjunyoung90

maximum-depth-of-binary-tree/kimjunyoung90.java

@@ -4,22 +4,3 @@ public int maxDepth(TreeNode root) {
         return 1 + Math.max(maxDepth(root.left), maxDepth(root.right));
     }
 }
-
-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;
-    }
-}