solves right side view in java

Author: anishLearnsToCode

Diff for: README.md

@@ -158,7 +158,7 @@
 | 190  | [Reverse Bits](https://leetcode.com/problems/reverse-bits)                                                                                                |                                       [![Java](assets/java.png)](src/ReverseBits.java) [![Python](assets/python.png)](python/reverse_bits.py)                                        |                                                                                                                                   |
 | 191  | [Number of One Bits](https://leetcode.com/problems/number-of-1-bits)                                                                                      |                                     [![Java](assets/java.png)](src/NumberOf1Bit.java) [![Python](assets/python.png)](python/number_of_1_bits.py)                                     |                                                                                                                                   |
 | 198  | [House Robber](https://leetcode.com/problems/house-robber)                                                                                                |                                       [![Java](assets/java.png)](src/HouseRobber.java) [![Python](assets/python.png)](python/house_robber.py)                                        |                                                                                                                                   |
-| 199  | [Binary Tree Right Side View](https://leetcode.com/problems/binary-tree-right-side-view)                                                                  |                                                                                                                                                                                      |                                                                                                                                   |
+| 199  | [Binary Tree Right Side View](https://leetcode.com/problems/binary-tree-right-side-view)                                                                  |                                                             [![Java](assets/java.png)](src/BinaryTreeRightSideView.java)                                                             |                                                                                                                                   |
 | 200  | [Number of Islands](https://leetcode.com/problems/number-of-islands)                                                                                      |                                                                                                                                                                                      |                                                                                                                                   |
 | 201  | [Bitwise AND of Numbers Range](https://leetcode.com/problems/bitwise-and-of-numbers-range)                                                                |                                                                                                                                                                                      |                                                                                                                                   |
 | 202  | [Happy Number](https://leetcode.com/problems/happy-number)                                                                                                |                                       [![Java](assets/java.png)](src/HappyNumber.java) [![Python](assets/python.png)](python/happy_number.py)                                        |                                                                                                                                   |

Diff for: src/BinaryTreeRightSideView.java

@@ -0,0 +1,22 @@
+// https://leetcode.com/problems/binary-tree-right-side-view
+// T: O(n)
+// S: O(log(n))
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class BinaryTreeRightSideView {
+    public List<Integer> rightSideView(TreeNode root) {
+        final List<Integer> result = new ArrayList<>();
+        rightSideView(root, result, 0);
+        return result;
+    }
+
+    private void rightSideView(TreeNode root, final List<Integer> result, int level) {
+        if (root == null) return;
+        if (level == result.size()) result.add(root.val);
+
+        rightSideView(root.right, result, level + 1);
+        rightSideView(root.left, result, level + 1);
+    }
+}