Create 0101-symmetric-tree.java

Author: adhamahmad

Diff for: java/0101-symmetric-tree.java

@@ -0,0 +1,17 @@
+class Solution {
+    public boolean isSymmetric(TreeNode root) {
+        return dfs(root.left,root.right);
+    }
+    private boolean dfs(TreeNode a, TreeNode b){
+        if(a == null && b == null ){
+            return true;
+        }
+        if(a == null || b == null ){
+            return false;
+        }else if(a.val != b.val){
+            return false;
+        }else{ // normal path
+            return dfs(a.left,b.right) && dfs(a.right,b.left) ;
+        }
+    }
+}