Merge pull request neetcode-gh#667 from KC10201/572-Subtree-of-Another-Tree.java-Fix-solution

572 subtree of another tree.java fix solution

Author: Ahmad-A0

java/572-Subtree-of-Another-Tree.java

@@ -1,17 +1,33 @@
-class Solution {
+// Solution: Recursive Approach
 
+// Time Complexity: O(n)
+// Extra Space Complexity: O(n)
+class Solution1 {
     public boolean isSubtree(TreeNode root, TreeNode subRoot) {
-        if (root == null && subRoot == null) return true;
-        if (root == null || subRoot == null) return false;
+        if (root == null && subRoot == null) {
+            return true;
+        }
+        if (root == null || subRoot == null) {
+            return false;
+        }
+        if (isSameTree(root, subRoot)) {
+            return true;
+        }
+        
+        return (isSubtree(root.left, subRoot) || isSubtree(root.right, subRoot));
+    }
+    
+    private boolean isSameTree(TreeNode root, TreeNode subRoot) {
+         if (root == null && subRoot == null) {
+            return true;
+        }
+        if (root == null || subRoot == null) {
+            return false;
+        }
         if (root.val == subRoot.val) {
-            return (
-                isSubtree(root.left, subRoot.left) &&
-                isSubtree(root.right, subRoot.right)
-            );
-        } else {
-            return (
-                isSubtree(root.left, subRoot) || isSubtree(root.right, subRoot)
-            );
+            return (isSameTree(root.left, subRoot.left) && isSameTree(root.right, subRoot.right));
         }
+        
+        return false;
     }
 }