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