https://leetcode.com/problems/binary-tree-right-side-view

medium/binary_tree_right_side_view.py

@@ -0,0 +1,33 @@
+# https://leetcode.com/problems/binary-tree-right-side-view
+
+from collections import deque
+from typing import Deque, List, Optional, Set, Tuple
+
+class TreeNode:
+    def __init__(self, val=0, left=None, right=None):
+        self.val = val
+        self.left = left
+        self.right = right
+
+class Solution:
+    def rightSideView(self, root: Optional[TreeNode]) -> List[int]:
+        result: List[int] = []
+        q: Deque[Tuple[TreeNode, int]] = deque()
+        levels: Set[int] = set()
+
+        if root is None:
+            return result
+
+        q.append((root, 0))
+        while len(q) > 0:
+            (curr, curr_level) = q.popleft()
+            if curr_level not in levels:
+                levels.add(curr_level)
+                result.append(curr.val)
+            if curr.right is not None:
+                q.append((curr.right, curr_level + 1))
+            if curr.left is not None:
+                q.append((curr.left, curr_level + 1))
+
+        return result
+