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)
13401	AtCoder KUPC2015: B. GUARDIANS
13400	AtCoder KUPC2015: A. 東京都
13399	AtCoder KUPC2014: L. べき乗数
13398	AtCoder KUPC2014: K. 弱点
13397	AtCoder KUPC2014: J. カード
13396	AtCoder KUPC2014: I. Rain
13395	AtCoder KUPC2014: H. 自転車走
13394	AtCoder KUPC2014: G. Darkroom
13393	AtCoder KUPC2014: F. テレパシー
13392	AtCoder KUPC2014: E. 何しちゃおっかな？
13391	AtCoder KUPC2014: D. ハミング
13390	AtCoder KUPC2014: C. 占い
13389	AtCoder KUPC2014: B. 数当てゲーム
13388	AtCoder KUPC2014: A. マッサージチェア
13387	AtCoder KUPC2013: K. encode/decode
13386	AtCoder KUPC2013: J. タイル置き
13385	AtCoder KUPC2013: I. σ
13384	AtCoder KUPC2013: H. N and K
13383	AtCoder KUPC2013: G. 自由研究
13382	AtCoder KUPC2013: F. ７歳教
13381	AtCoder KUPC2013: E. すごろく
13380	AtCoder KUPC2013: D. カーペット
13379	AtCoder KUPC2013: C. チョコレート
13378	AtCoder KUPC2013: B. ライオン
13377	AtCoder KUPC2013: A. 旧総合研究７号館
13376	AtCoder KUPC2012PR: D. A mul B Problem
13375	AtCoder KUPC2012PR: C. パニクるな
13374	AtCoder KUPC2012PR: B. String Sorting
13373	AtCoder KUPC2012PR: A. Wikipedia
13372	AtCoder KUPC2012: I. 宝探し
13371	AtCoder KUPC2012: H. 植林
13370	AtCoder KUPC2012: G. 村
13369	AtCoder KUPC2012: F. Acceleration of Network
13368	AtCoder KUPC2012: E. じゃんけん
13367	AtCoder KUPC2012: D. 権力
13366	AtCoder KUPC2012: C. ソーシャル
13365	AtCoder KUPC2012: B. 簡易オセロ
13364	AtCoder KUPC2012: K. XOR回廊
13363	AtCoder KUPC2012: J. 刺身
13362	AtCoder KUPC2012: A. アルデンテ
13361	AtCoder KEYENCE2021: F. Keyence Repetition
13360	AtCoder KEYENCE2021: E. Greedy Ant
13359	AtCoder KEYENCE2021: D. Choosing Up Sides
13358	AtCoder KEYENCE2021: C. Robot on Grid
13357	AtCoder KEYENCE2021: B. Mex Boxes
13356	AtCoder KEYENCE2021: A. Two Sequences 2
13355	AtCoder KEYENCE2020: F. Monochromization
13354	AtCoder KEYENCE2020: E. Bichromization
13353	AtCoder KEYENCE2020: D. Swap and Flip
13352	AtCoder KEYENCE2020: C. Subarray Sum

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

13401

AtCoder KUPC2015: B. GUARDIANS

13400

AtCoder KUPC2015: A. 東京都

13399

AtCoder KUPC2014: L. べき乗数

13398

AtCoder KUPC2014: K. 弱点

13397

AtCoder KUPC2014: J. カード

13396