solves #2331: Evaluate Boolean Binary Tree in java

Author: anishLearnsToCode

Diff for: README.md

@@ -748,7 +748,7 @@
 | 2316 | [Count Unreachable Pairs of Nodes in an Undirected Graph](https://leetcode.com/problems/count-unreachable-pairs-of-nodes-in-an-undirected-graph)                       |                                                                [![Python](assets/python.png)](python/count_unreachable_pair_of_node_in_an_undirectable_graph.py)                                                                 |                                                                                                                                   |
 | 2319 | [Check if Matrix Is X-Matrix](https://leetcode.com/problems/check-if-matrix-is-x-matrix)                                                                               |                                                                                       [![Java](assets/java.png)](src/CountAsterisks.java)                                                                                        |                                                                                                                                   |
 | 2325 | [Decode the Message](https://leetcode.com/problems/decode-the-message)                                                                                                 |                                                                                      [![Java](assets/java.png)](src/DecodeTheMessage.java)                                                                                       |                                                                                                                                   |
-| 2331 | [Evaluate Boolean Binary Tree](https://leetcode.com/problems/evaluate-boolean-binary-tree)                                                                             |                                                                                                                                                                                                                                  |                                                                                                                                   |
+| 2331 | [Evaluate Boolean Binary Tree](https://leetcode.com/problems/evaluate-boolean-binary-tree)                                                                             |                                                                                  [![Java](assets/java.png)](src/EvaluateBooleanBinaryTree.java)                                                                                  |                                                                                                                                   |
 | 2335 | [Minimum Amount of Time to Fill Cups](https://leetcode.com/problems/minimum-amount-of-time-to-fill-cups)                                                               |                                                                                                                                                                                                                                  |                                                                                                                                   |
 | 2439 | [Minimize Maximum of Array](https://leetcode.com/problems/minimize-maximum-of-array)                                                                                   |                                                                               [![Python](assets/python.png)](python/minimize_maximum_of_array.py)                                                                                |                                                                                                                                   |
 | 2341 | [Maximum Number of Pairs in Array](https://leetcode.com/problems/maximum-number-of-pairs-in-array)                                                                     |                                                                                                                                                                                                                                  |                                                                                                                                   |

Diff for: src/EvaluateBooleanBinaryTree.java

@@ -0,0 +1,21 @@
+// https://leetcode.com/problems/evaluate-boolean-binary-tree
+// T: O(N)
+// S: O(log(N))
+
+public class EvaluateBooleanBinaryTree {
+    public boolean evaluateTree(TreeNode root) {
+        if (isLeafNode(root)) {
+            return root.val == 1;
+        }
+
+        if (root.val == 2) {
+            return evaluateTree(root.left) || evaluateTree(root.right);
+        }
+
+        return evaluateTree(root.left) && evaluateTree(root.right);
+    }
+
+    private boolean isLeafNode(TreeNode root) {
+        return root.left == null && root.right == null;
+    }
+}