feat(work): add solution for Binary Tree Right Side View problem

work/1/Medium/Tree/199.binary-tree-right-side-view.py

@@ -0,0 +1,79 @@
+"""
+199. Binary Tree Right Side View
+Difficulty: Medium
+https://leetcode.com/problems/binary-tree-right-side-view/
+
+──────────────────────────────────────────────────
+
+Given the root of a binary tree, imagine yourself standing on the
+right side of it, return the values of the nodes you can see ordered
+from top to bottom.
+
+
+
+Example 1:
+
+Input: root = [1,2,3,null,5,null,4]
+
+Output: [1,3,4]
+
+Explanation:
+
+Example 2:
+
+Input: root = [1,2,3,4,null,null,null,5]
+
+Output: [1,3,4,5]
+
+Explanation:
+
+Example 3:
+
+Input: root = [1,null,3]
+
+Output: [1,3]
+
+Example 4:
+
+Input: root = []
+
+Output: []
+
+
+
+Constraints:
+
+        • The number of nodes in the tree is in the range [0, 100].
+
+        • -100 <= Node.val <= 100
+"""
+
+# Definition for a binary tree node.
+# class TreeNode:
+#     def __init__(self, val=0, left=None, right=None):
+#         self.val = val
+#         self.left = left
+#         self.right = right
+from collections import deque
+
+
+class Solution:
+    def rightSideView(self, root: Optional[TreeNode]) -> List[int]:
+        res = []
+        q = deque([root])
+
+        while q:
+            rightSide = None
+            qLen = len(q)
+
+            for i in range(qLen):
+                node = q.popleft()
+                if node:
+                    rightSide = node
+                    q.append(node.left)
+                    q.append(node.right)
+
+            if rightSide:
+                res.append(rightSide.val)
+
+        return res