solves sum of root to leaf binary numbers

Author: anishLearnsToCode

README.md

@@ -276,7 +276,7 @@
 | 1013 | [Partition Array into Three Parts with equal Sum](https://leetcode.com/problems/partition-array-into-three-parts-with-equal-sum)                     |                                                                                                                                                                             |                                                                                                                                   |
 | 1018 | [Binary Prefix Divisible by 5](https://leetcode.com/problems/binary-prefix-divisible-by-5)                                                           |                                                        [![Java](assets/java.png)](src/BinaryPrefixDivisibleBy5.java)                                                        |                                                                                                                                   |
 | 1021 | [Remove Outermost Parenthesis](https://leetcode.com/problems/remove-outermost-parentheses)                                                           |                                                       [![Java](assets/java.png)](src/RemoveOutermostParentheses.java)                                                       |                                                                                                                                   |
-| 1022 | [Sum of Root to Leaf Binary Numbers](https://leetcode.com/problems/sum-of-root-to-leaf-binary-numbers)                                               |                                                                                                                                                                             |                                                                                                                                   |
+| 1022 | [Sum of Root to Leaf Binary Numbers](https://leetcode.com/problems/sum-of-root-to-leaf-binary-numbers)                                               |                                                      [![Java](assets/java.png)](src/SumOfRootToLeafBinaryNumbers.java)                                                      |                                                                                                                                   |
 | 1025 | [Divisor Game](https://leetcode.com/problems/divisor-game)                                                                                           |                                                                                                                                                                             |                                                                                                                                   |
 | 1029 | [Two City Scheduling](https://leetcode.com/problems/two-city-scheduling)                                                                             |                                                                                                                                                                             |                                                                                                                                   |
 | 1030 | [Matrix Cells in Distance Order](https://leetcode.com/problems/matrix-cells-in-distance-order)                                                       |                                                                                                                                                                             |                                                                                                                                   |

src/SumOfRootToLeafBinaryNumbers.java

@@ -0,0 +1,11 @@
+public class SumOfRootToLeafBinaryNumbers {
+    public int sumRootToLeaf(TreeNode root) {
+        return sumRootToLeaf(root, 0);
+    }
+
+    private int sumRootToLeaf(TreeNode root, int sum) {
+        if (root == null) return 0;
+        if (root.left == null && root.right == null) return sum + root.val;
+        return sumRootToLeaf(root.left, (sum + root.val) << 1) + sumRootToLeaf(root.right, (sum + root.val) << 1);
+    }
+}