Solved Arai60/276. Paint Fence #30
Open
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
kazukiii
reviewed
Jun 16, 2025
Comment on lines
+66
to
+67
| self.remove(key) | ||
| self.add(key, node.val) |
There was a problem hiding this comment.
node.valの代わりにnodeを渡した方が良いということですね。
putでvalを入れたかったのでaddの中で作るように統一したんですが、確かに再利用できることを考えるとputでnode作ってnodeを渡す方が良いですね
Comment on lines
+87
to
+88
| if self.sentinel.previous == self.sentinel: | ||
| self.sentinel.previous = node |
There was a problem hiding this comment.
ここはLinkedListが空のケース判定だと思いますが、おそらく不要かなと思いました。
There was a problem hiding this comment.
sentinel.previousにLRUのnodeを入れている実装なんですが、基本は追加するノード周りの更新作業しかしないので末尾がつながるようにするには、一つ目のnodeを入れる時につないでおく必要があると思っています。
putでキャパオーバーの時にsentinel.previousを消すときに、ここがないとsentinel.previousは初期状態のまま変更されないので上手くいかないと思います。（ちゃんと実行してなくてすみません）
| ```python | ||
| class Solution: | ||
| def countWays(self, n: int, k: int) -> int: | ||
| ways_to_index: dict[int, int] = {} |
There was a problem hiding this comment.
バケット探索・衝突解決等考えると、配列の方が若干パフォーマンスが高いかもしれないと思いました。メモリ効率も良さそうです。（そもそも直前とその前の要素のみ保持すればという話もありますが)
There was a problem hiding this comment.
そうなんですね。割と癖でインデックスまでの〇〇を辞書型にしてしまっている節があるので気を付けようと思います。
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
2 participants
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
問題文：https://www.geeksforgeeks.org/problems/painting-the-fence3727/1
（LeetCode Premiumにつき、GeeksForGeeksで代用）