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Over 20,000 problems available: AMC 8/10/12 and AIME problems from 2010-2024; USAJMO/USAMO problems from 2002-2024; USACO problems from 2014 to 2024 (all divisions); all Codeforces, AtCoder and DMOJ problems. If you leave the search field blank, it returns all problems with the specified type.

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  • AMC 8: [year] AMC 8 Problem #, Ex: 2013 AMC 8 Problem 1
  • AMC 10: [year] AMC 10A Problem # OR [year] AMC 10B Problem #, Ex: 2015 AMC 10A Problem 16
  • AMC 12: [year] AMC 12A Problem # OR [year] AMC 12B Problem #, Ex: 2021 AMC 12B Problem 25
  • AIME: [year] AIME I Problem # OR [year] AIME II Problem #, Ex: 2013 AIME I Problem 8
  • USAJMO/USAMO: [year] USAJMO/USAMO Problem #, Ex: 2023 USAJMO Problem 1
  • Codeforces: Codeforces [contest id (e.g. 101)][problem id (e.g. A, B, C)]: [Codeforces problem name], Ex: Codeforces 1336F: Journey
  • AtCoder: AtCoder [contest id (e.g. ABC314, ARC164, ZONE2021)]: [problem id (A, B, C)]. [Problem name], Ex: AtCoder ZONE2021: E. Sneaking
  • DMOJ: DMOJ [contest name (if applicable)] [problem number (e.g. P1)] - [Problem name], Ex: DMOJ Yet Another Contest 3 P1 - Shell Swap Scam
  • USACO: [year] [contest month (e.g. January, US Open)], [division (e.g. Gold)]: [Problem name], Ex: USACO 2023 US Open Contest, Bronze: Rotate and Shift

ID Problem Name (click to add insights/hints, view summary of insights/hints and similar problems)
12955 AtCoder JOI2021YO1B: A. 帰省 (Homecoming)
12954 AtCoder JOI2021YO1A: C. 共通要素 (Common Elements)
12953 AtCoder JOI2021YO1A: B. JOI ソート (JOI Sort)
12952 AtCoder JOI2021YO1A: A. 2 番目に大きい整数 (The Second Largest Integer)
12951 AtCoder JOI2020HO: E. 火事 (Fire)
12950 AtCoder JOI2020HO: D. オリンピックバス (Olympic Bus)
12949 AtCoder JOI2020HO: C. スタンプラリー 3 (Collecting Stamps 3)
12948 AtCoder JOI2020HO: B. JJOOII 2 (JJOOII 2)
12947 AtCoder JOI2020HO: A. 長いだけのネクタイ (Just Long Neckties)
12946 AtCoder JOI2020YO2: E. じゃんけん式 (Rock-Scissors-Paper Expression)
12945 AtCoder JOI2020YO2: D. テンキー (Tenkey)
12944 AtCoder JOI2020YO2: C. 桁和 (Digit Sum)
12943 AtCoder JOI2020YO2: B. いちご (Strawberry)
12942 AtCoder JOI2020YO2: A. ポスター (Poster)
12941 AtCoder JOI2020YO1C: C. 最長昇順連続部分列 (Longest Ascending Contiguous Subsequence)
12940 AtCoder JOI2020YO1C: B. キャピタリゼーション (Capitalization)
12939 AtCoder JOI2020YO1C: A. X に最も近い値 (The Nearest Value)
12938 AtCoder JOI2020YO1B: C. 最頻値 (Mode)
12937 AtCoder JOI2020YO1B: B. 文字列の反転 (Inversion of a String)
12936 AtCoder JOI2020YO1B: A. 試験 (Exam)
12935 AtCoder JOI2020YO1A: C. マージ (Merge)
12934 AtCoder JOI2020YO1A: B. 母音を数える (Counting Vowels)
12933 AtCoder JOI2020YO1A: A. 3 つの整数 (Three Integers)
12932 AtCoder JOI2019HO: E. 珍しい都市 (Unique Cities)
12931 AtCoder JOI2019HO: D. コイン集め (Coin Collecting)
12930 AtCoder JOI2019HO: C. たのしいたのしいたのしい家庭菜園 (Growing Vegetables is Fun 3)
12929 AtCoder JOI2019HO: B. 展覧会 (Exhibition)
12928 AtCoder JOI2019HO: A. 勇者ビ太郎 (Bitaro the Brave)
12927 AtCoder JOI2019YO: F. 座席 (Seats)
12926 AtCoder JOI2019YO: E. イルミネーション (Illumination)
12925 AtCoder JOI2019YO: D. 日本沈没 (Japan Sinks)
12924 AtCoder JOI2019YO: C. マルバツスタンプ (Circle Cross Stamps)
12923 AtCoder JOI2019YO: B. すごろくと駒 (Sugoroku and Pieces)
12922 AtCoder JOI2019YO: A. ソーシャルゲーム (Social Game)
12921 AtCoder JOI2018HO: E. 毒蛇の脱走 (Snake Escaping)
12920 AtCoder JOI2018HO: D. 定期券 (Commuter Pass)
12919 AtCoder JOI2018HO: C. 団子職人 (Dango Maker)
12918 AtCoder JOI2018HO: B. 美術展 (Art Exhibition)
12917 AtCoder JOI2018HO: A. ストーブ (Stove)
12916 AtCoder JOI2018YO: F. L番目のK番目の数 (LthKthNumber)
12915 AtCoder JOI2018YO: E. 森林伐採（Deforestation）
12914 AtCoder JOI2018YO: D. 水ようかん (Mizuyokan)
12913 AtCoder JOI2018YO: C. 幹線道路 (Trunk Road)
12912 AtCoder JOI2018YO: B. 双六 (Sugoroku)
12911 AtCoder JOI2018YO: A. 鉛筆 (Pencils)
12910 AtCoder JOI2017YO: F. ヘビの JOI 君 (Snake JOI)
12909 AtCoder JOI2017YO: E. 尾根 (Ridge)
12908 AtCoder JOI2017YO: D. ぬいぐるみの整理 (Plush Toys)
12907 AtCoder JOI2017YO: C. 休憩スペース (Refreshment Area)
12906 AtCoder JOI2017YO: B. ポイントカード (Point Card)
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