AtCoder記事まとめ

AtCoder投稿記事まとめリンク集

解法

動的計画法

ABC011 C (diff:810)
ABC220 C (diff:664)
ABC248 C (diff:787)
ABC261 D (diff:801)
ABC285 E (diff:1466)
ABC355 D (diff:735)

ビットDP

ABC332 E (diff:1883)

BFS

ABC168 D (diff:804)
ABC332 D (diff:1175)
ABC383 C (diff:750)

DFS

ABC146 D (diff:1192)
ABC184 D (diff:1276)

ダイクストラ法

ABC340 D (diff:784)

UnionFind

ABC285 D (diff:663)
ABC351 D (diff:974)

尺取法

ABC229 D (diff:745)

累積和

ABC337 D (diff:760)

二分探索

ABC146 C (diff:741)
ABC248 D (diff:793)
ABC257 C (diff:678)

ビット全探索

ABC128 C (diff:805)
ABC197 C (diff:809)

素因数分解

ABC254 D (diff:1191)

幾何学

ABC197 D (diff:831)

二分探索

ABC195 D (diff:945)
ABC217 D (diff:802)
ABC255 D (diff:788)
ABC321 D (diff:806)

ビット演算

ABC261 E (diff:1261)

排他的論理和

ABC295 D (diff:939)

その他

ピラミッド数列

ABC336 D (diff:991)

グリッド走査

ABC241 C (diff:664)

モジュロ演算

ABC146 E (diff:1762)

スタック

ABC307 D (diff:666)

ヒープキュー

ABC141 D (diff:823)

境界問題

ABC180 D (diff:752)

未カテゴリ

ABC006 B (diff:813)
ABC035 B (diff:804)
ABC051 B (diff:784)
ABC061 C (diff:808)
ABC197 C (diff:809)
ABC245 D (diff:815)

AtCoder開催順

ABC006 B (diff:813)
ABC011 C (diff:810)
ABC035 B (diff:804)
ABC051 B (diff:784)
ABC061 C (diff:808)
ABC128 C (diff:805)
ABC141 D (diff:823)
ABC146 C (diff:741), ABC146 D (diff:1192), ABC146 E (diff:1762)
ABC168 D (diff:804)
ABC180 D (diff:752)
ABC184 D (diff:1276)
ABC195 D (diff:945)
ABC197 B (diff:96), ABC197 C (diff:809), ABC197 D (diff:831)
ABC217 D (diff:802)
ABC220 C (diff:664)
ABC229 D (diff:745)
ABC241 C (diff:664)
ABC245 D (diff:815)
ABC248 C (diff:787), ABC248 D (diff:793)
ABC254 D (diff:1191)
ABC255 D (diff:788)
ABC257 C (diff:678)
ABC261 D (diff:801), ABC261 E (diff:1261)
ABC264 C (diff:758)
ABC285 D (diff:663), ABC285 E (diff:1466)
ABC287 D (diff:786)
ABC292 E (diff:792)
ABC295 D (diff:939)
ABC307 D (diff:666)
ABC321 D (diff:806)
ABC332 D (diff:1175), ABC332 E (diff:1883)
ABC336 D (diff:991)
ABC337 D (diff:760)
ABC340 D (diff:784)
ABC351 D (diff:974)
ABC355 D (diff:735)
ABC362 C (diff:521)
ABC368 D (diff:816)
ABC383 C (diff:750)

証明作業

数学的帰納法

ABC011 C (diff:810)
ABC261 D (diff:801)
ABC285 E (diff:1466)

エッセンス

BFS

ABC383 C (diff:750)

動的計画法

ABC011 C (diff:810)

動的計画法(文章説明)

ABC248 C (diff:787)

二分探索

ABC217 D (diff:802)

pythonモジュール

• from itertools import product

• from sortedcontainers import SortedList
  ABC141 D (diff:823)
  ABC217 D (diff:802)
  ABC355 D (diff:735)

競技プログラミングを解いているときの感情

1. 30分以上かけてAC出来なければ諦めると決めていても、解けそうな感じがすると時間を忘れて解きにかかってしまう。
2. 苦労して解いた問題のdiffを見て、予想より低かったらACしてもガッカリする。
3. D問題を5問連続して解けたら、D問題レベル楽じゃね？って感じるものの、難問C問題に遭遇して勘違いだと思い知る。
4. 動的計画法の問題は解けても復元出来ないことがよくある。
5. 開発作業で、コードの中にDFS/BFS/UnionFind/DPを使うチャンスがないか考えてしまう。
6. ある程度慣れくると、diff:1000未満の問題は意地でも解いてやろうという気になって時間を忘れる。
7. TLEくらいまくって苦戦してた問題に対して、サクサクACが進むと脳汁が出る。
8. 初期は動的計画法に対し苦手意識を感じるが、慣れてくると(解ける解けないは別とし)楽しくなってくる。
9. D問題に慣れてきた時に、茶色コーダーの壁が妙に高いことに驚く。
10. C問題の中に難問が紛れ込んでいて、A→B→C→D→Eの順番で解かない方が良いと気づく。

バックアップ(別解)

ABC217 D (diff:802)

復習

ABC011 C (diff:810)
ABC272 D (diff:804)

失敗事例

ABC003 B (diff:668)
ABC315 D (diff:1531)
ABC332 E (diff:1883)