Starlight: List of Problems

Over 20,000 problems available. AMC 8/10/12 and AIME problems from 2010-2023; USAJMO/USAMO problems from 2002-2023 available. USACO problems from 2014 to 2023 (all divisions). Codeforces, AtCoder, DMOJ problems are added daily around 04:00 AM UTC, which may cause disruptions.

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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)
11901	AtCoder CADDI2018B: D. Harlequin
11900	AtCoder CADDI2018B: C. Product and GCD
11899	AtCoder BITFLYER2018-QUAL: E. 祝日
11898	AtCoder BITFLYER2018-QUAL: D. ハンコ
11897	AtCoder BITFLYER2018-QUAL: C. 徒歩圏内
11896	AtCoder BITFLYER2018-QUAL: B. 洋菓子店
11895	AtCoder BITFLYER2018-QUAL: A. 本選参加者数
11894	AtCoder BITFLYER2018-FINAL: H. 三角形と格子点
11893	AtCoder BITFLYER2018-FINAL: G. Following Permutations
11892	AtCoder BITFLYER2018-FINAL: F. 配信パズル
11891	AtCoder BITFLYER2018-FINAL: E. 数式とクエリ
11890	AtCoder BITFLYER2018-FINAL: D. 数列 XOR
11889	AtCoder BITFLYER2018-FINAL: C. 部分文字列と括弧
11888	AtCoder BITFLYER2018-FINAL: B. 交通費
11887	AtCoder BITFLYER2018-FINAL: A. 値札
11886	AtCoder BIRTHDAY0410: X. この問題はほんとうにひどい問題であるため，できれば先に他の問題のほうをお楽しみいただければと思っておりまして，ですので他の問題を通し終えて暇になり，かつその暇を
11885	AtCoder BIRTHDAY0410: F. おいらの素数生成式
11884	AtCoder BIRTHDAY0410: E. 排他的☆論理和っ！！
11883	AtCoder BIRTHDAY0410: D. 先生と遺書
11882	AtCoder BIRTHDAY0410: C. ロ　シ　ア
11881	AtCoder BIRTHDAY0410: B. ライスゲーム
11880	AtCoder BIRTHDAY0410: A. A + B
11879	AtCoder BCU30: F. 数列と計算
11878	AtCoder BCU30: E. スライドパズル
11877	AtCoder BCU30: D. 数直線
11876	AtCoder BCU30: C. クロスワード
11875	AtCoder BCU30: B. 数字パズル
11874	AtCoder BCU30: A. すごろく
11873	AtCoder BCU30-2019-QUAL: A. Bullet of Flame
11872	AtCoder BCU30-2019: B. Interval Addition
11871	AtCoder BCU30-2019: A. Wolf Keyboard
11870	AtCoder BCU30-2018-QUAL: A. Age
11869	AtCoder BCU30-2018: B. Spring Water
11868	AtCoder BCU30-2018: A. Ball
11867	AtCoder AUTUMN_FEST: K. Batch Style Mastermind
11866	AtCoder AUTUMN_FEST: J. Ninja of Train
11865	AtCoder AUTUMN_FEST: I. Pyramid
11864	AtCoder AUTUMN_FEST: H. U・N・C・O
11863	AtCoder AUTUMN_FEST: G. Bit Map
11862	AtCoder AUTUMN_FEST: F. Vinculum
11861	AtCoder AUTUMN_FEST: E. Be Together
11860	AtCoder AUTUMN_FEST: D. Don't Think Seriously!
11859	AtCoder AUTUMN_FEST: C. Cards
11858	AtCoder AUTUMN_FEST: B. 3Match
11857	AtCoder AUTUMN_FEST: A. Irregular Contest
11856	AtCoder ATCODER11LIVE: A. Turn Right
11855	AtCoder ATC002: C. 最適二分探索木
11854	AtCoder ATC002: B. n^p mod m
11853	AtCoder ASPROCON9: A. Shift Scheduling
11852	AtCoder ASPROCON8: A. Automated Painting Line

Problem Name (click to add insights/hints, view summary of insights/hints and similar problems)

11901

AtCoder CADDI2018B: D. Harlequin

11900

AtCoder CADDI2018B: C. Product and GCD

11899

AtCoder BITFLYER2018-QUAL: E. 祝日

11898

AtCoder BITFLYER2018-QUAL: D. ハンコ

11897

AtCoder BITFLYER2018-QUAL: C. 徒歩圏内

11896