solves univalues binary tree

Author: anishLearnsToCode

README.md

@@ -260,7 +260,7 @@
 | 949 | [Largest Time for Given Digits](https://leetcode.com/problems/largest-time-for-given-digits) | |
 | 953 | [Verifying an Alien Dictionary](https://leetcode.com/problems/verifying-an-alien-dictionary) | [![Java](assets/java.png)](src/VerifyAnAlienDictionary.java) |
 | 961 | [N-Repeated Elements in Size 2N Array](https://leetcode.com/problems/n-repeated-element-in-size-2n-array) | [![Java](assets/java.png)](src/NRepeatedElementInSizeNArray.java) |
-| 965 | [Univalued Binary Tree](https://leetcode.com/problems/univalued-binary-tree) | |
+| 965 | [Univalued Binary Tree](https://leetcode.com/problems/univalued-binary-tree) | [![Java](assets/java.png)](src/UnivaluedBinaryTree.java) |
 | 970 | [Powerful Integers](https://leetcode.com/problems/powerful-integers) | |
 | 976 | [Largest Perimeter Triangle](https://leetcode.com/problems/largest-perimeter-triangle) | |
 | 977 | [Squares of a Sorted Array](https://leetcode.com/problems/squares-of-a-sorted-array) | |

src/UnivaluedBinaryTree.java

@@ -0,0 +1,14 @@
+public class UnivaluedBinaryTree {
+    private int val;
+
+    public boolean isUnivalTree(TreeNode root) {
+        val = root.val;
+        return isUnival(root);
+    }
+
+    private boolean isUnival(TreeNode root) {
+        if (root == null) return true;
+        if (root.val != val) return false;
+        return isUnival(root.left) && isUnival(root.right);
+    }
+}