Merge pull request #20 from lxmn22nov/lxmn7

Java: Binary Tree

Author: akscoder082003

Java/BinaryTree/SymmetricTree.java

@@ -0,0 +1,21 @@
+/*
+ * PROBLEM: 101 : Symmetric Tree
+ */
+public class SymmetricTree {
+    public boolean isSymmetric(TreeNode root) {
+        if (root == null) {
+            return true;
+        }
+        return isMirror(root.left, root.right);
+    }
+
+    private boolean isMirror(TreeNode node1, TreeNode node2) {
+        if (node1 == null && node2 == null) {
+            return true;
+        }
+        if (node1 == null || node2 == null) {
+            return false;
+        }
+        return node1.val == node2.val && isMirror(node1.left, node2.right) && isMirror(node1.right, node2.left);
+    }
+}