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)
12251	AtCoder DDCC2016-FINAL: B. デュアルカット
12250	AtCoder DDCC2016-FINAL: A. 正方形のチップ
12249	AtCoder DDCC2020-QUAL: F. DISCOSMOS
12248	AtCoder DDCC2020-QUAL: E. Majority of Balls
12247	AtCoder DDCC2020-QUAL: D. Digit Sum Replace
12246	AtCoder DDCC2020-QUAL: C. Strawberry Cakes
12245	AtCoder DDCC2020-QUAL: B. Iron Bar Cutting
12244	AtCoder DDCC2020-QUAL: A. DDCC Finals
12243	AtCoder DDCC2020-FINAL: D. Pars/ey
12242	AtCoder DDCC2020-FINAL: C. Smaller-Suffix-Free Sequences
12241	AtCoder DDCC2020-FINAL: B. Hawker on Graph
12240	AtCoder DDCC2020-FINAL: A. Div/de
12239	AtCoder DDCC2019-MACHINE: B. 装置実装問題（決勝進出者のみ）
12238	AtCoder DDCC2019-MACHINE: A. シミュレータ問題（予選問題）
12237	AtCoder DDCC2019-FINAL: E. 飾りつけ (Decoration)
12236	AtCoder DDCC2019-FINAL: D. DISCO!
12235	AtCoder DDCC2019-FINAL: C. 光の反射 (Reflection of Light)
12234	AtCoder DDCC2019-FINAL: B. 大吉数列 (Array of Fortune)
12233	AtCoder DDCC2019-FINAL: A. レース (Race)
12232	AtCoder DDCC2019-QUAL: D. チップ・ストーリー　～黄金編～
12231	AtCoder DDCC2019-QUAL: C. チップ・ストーリー　～白銀編～
12230	AtCoder DDCC2019-QUAL: B. チップ・ストーリー　～漆黒編～
12229	AtCoder DDCC2019-QUAL: A. チップ・ストーリー　～無色編～
12228	AtCoder DDCC2017-QUAL: D. 石
12227	AtCoder DDCC2017-QUAL: C. 収納
12226	AtCoder DDCC2017-QUAL: B. 鉛筆
12225	AtCoder DDCC2017-QUAL: A. DDCC型文字列
12224	AtCoder DDCC2017-FINAL: E. 足のばし
12223	AtCoder DDCC2017-FINAL: D. なめらかな木
12222	AtCoder DDCC2017-FINAL: C. グラフいじり
12221	AtCoder DDCC2017-FINAL: B. GCDロボット
12220	AtCoder DDCC2017-FINAL: A. 正方形のチップ２
12219	AtCoder CPSCO2019-S4: F. Lost Tree
12218	AtCoder CPSCO2019-S4: E. ox Concatenation
12217	AtCoder CPSCO2019-S4: D. Boring Sequence
12216	AtCoder CPSCO2019-S4: C. Make a Team
12215	AtCoder CPSCO2019-S4: B. Meeting
12214	AtCoder CPSCO2019-S4: A. Swimming
12213	AtCoder CPSCO2019-S3: G. Grand Election
12212	AtCoder CPSCO2019-S3: F. Flexible Permutation
12211	AtCoder CPSCO2019-S3: E. Enumerate Xor Sum
12210	AtCoder CPSCO2019-S3: D. Decode RGB Sequence
12209	AtCoder CPSCO2019-S3: C. Camp Reception
12208	AtCoder CPSCO2019-S3: B. Balloons
12207	AtCoder CPSCO2019-S3: A. ASOKO
12206	AtCoder CPSCO2019-S2: G. MSTX
12205	AtCoder CPSCO2019-S2: F. Treasure Collector
12204	AtCoder CPSCO2019-S2: E. Mogu Mogu Gummi
12203	AtCoder CPSCO2019-S2: D. Two Piles
12202	AtCoder CPSCO2019-S2: C. Delicious Burgers

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

12251

AtCoder DDCC2016-FINAL: B. デュアルカット

12250

AtCoder DDCC2016-FINAL: A. 正方形のチップ

12249

AtCoder DDCC2020-QUAL: F. DISCOSMOS

12248

AtCoder DDCC2020-QUAL: E. Majority of Balls

12247

AtCoder DDCC2020-QUAL: D. Digit Sum Replace

12246