solves #2236: Root Equals Sum of Children in java

Author: anishLearnsToCode

Diff for: .gitignore

@@ -2,3 +2,4 @@
 out
 venv
 *.iml
+.DS_Store

Diff for: README.md

@@ -727,7 +727,7 @@
 | 2229 | 🔒 [Check if an array is consecutive](https://leetcode.com/problems/check-if-an-array-is-consecutive)                                                                  |                                                                                                                                                                                                                                  |                                                                                                                                   |
 | 2231 | [Largest Number After Digit Swaps by Parity](https://leetcode.com/problems/largest-number-after-digit-swaps-by-parity)                                                 |                                                                            [![Java](assets/java.png)](src/LargestNumberAfterDigitSwapsByParity.java)                                                                             |                                                                                                                                   |
 | 2235 | [Add Two Integers](https://leetcode.com/problems/add-two-integers)                                                                                                     |                                                                                       [![Java](assets/java.png)](src/AddTwoIntegers.java)                                                                                        |                                                                                                                                   |
-| 2236 | [Root Equals Sum of Children](https://leetcode.com/problems/root-equals-sum-of-children)                                                                               |                                                                                                                                                                                                                                  |                                                                                                                                   |
+| 2236 | [Root Equals Sum of Children](https://leetcode.com/problems/root-equals-sum-of-children)                                                                               |                                                                                   [![Java](assets/java.png)](src/RootEqualsSumOfChildren.java)                                                                                   |                                                                                                                                   |
 | 2239 | [Find Closest Number to Zero](https://leetcode.com/problems/find-closest-number-to-zero)                                                                               |                                                                                                                                                                                                                                  |                                                                                                                                   |
 | 2243 | [Calculate Digit Sum of a String](https://leetcode.com/problems/calculate-digit-sum-of-a-string)                                                                       |                                                                                                                                                                                                                                  |                                                                                                                                   |
 | 2248 | [Intersection of Multiple Arrays](https://leetcode.com/problems/intersection-of-multiple-arrays)                                                                       |                                                                                                                                                                                                                                  |                                                                                                                                   |

Diff for: src/RootEqualsSumOfChildren.java

@@ -0,0 +1,9 @@
+// https://leetcode.com/problems/root-equals-sum-of-children
+// T: O(1)
+// S: O(1)
+
+public class RootEqualsSumOfChildren {
+    public boolean checkTree(TreeNode root) {
+        return root.val == root.left.val + root.right.val;
+    }
+}