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)
7201	Codeforces 1574A: Regular Bracket Sequences
7200	Codeforces 1573B: Swaps
7199	Codeforces 1573A: Countdown
7198	Codeforces 1572F: Stations
7197	Codeforces 1572E: Polygon
7196	Codeforces 1572D: Bridge Club
7195	Codeforces 1572C: Paint
7194	Codeforces 1572B: Xor of 3
7193	Codeforces 1572A: Book
7192	Codeforces 1571J: Two Railroads
7191	Codeforces 1571I: Physical Examination
7190	Codeforces 1571H: Laser Beams
7189	Codeforces 1571G: A Battle Against a Dragon
7188	Codeforces 1571F: Kotlinforces
7187	Codeforces 1571E: Fix the String
7186	Codeforces 1571D: Sweepstake
7185	Codeforces 1571C: Rhyme
7184	Codeforces 1571B: Epic Novel
7183	Codeforces 1571A: Sequence of Comparisons
7182	Codeforces 1569F: Palindromic Hamiltonian Path
7181	Codeforces 1569E: Playoff Restoration
7180	Codeforces 1569D: Inconvenient Pairs
7179	Codeforces 1569C: Jury Meeting
7178	Codeforces 1569B: Chess Tournament
7177	Codeforces 1569A: Balanced Substring
7176	Codeforces 1567F: One-Four Overload
7175	Codeforces 1567E: Non-Decreasing Dilemma
7174	Codeforces 1567D: Expression Evaluation Error
7173	Codeforces 1567C: Carrying Conundrum
7172	Codeforces 1567B: MEXor Mixup
7171	Codeforces 1567A: Domino Disaster
7170	Codeforces 1566H: Xor-quiz
7169	Codeforces 1566G: Four Vertices
7168	Codeforces 1566F: Points Movement
7167	Codeforces 1566E: Buds Re-hanging
7166	Codeforces 1566D2: Seating Arrangements (hard version)
7165	Codeforces 1566D1: Seating Arrangements (easy version)
7164	Codeforces 1566C: MAX-MEX Cut
7163	Codeforces 1566B: MIN-MEX Cut
7162	Codeforces 1566A: Median Maximization
7161	Codeforces 1562F: Tubular Bells
7160	Codeforces 1562E: Rescue Niwen!
7159	Codeforces 1562D2: Two Hundred Twenty One (hard version)
7158	Codeforces 1562D1: Two Hundred Twenty One (easy version)
7157	Codeforces 1562C: Rings
7156	Codeforces 1562B: Scenes From a Memory
7155	Codeforces 1562A: The Miracle and the Sleeper
7154	Codeforces 1561D1: Up the Strip (simplified version)
7153	Codeforces 1561C: Deep Down Below
7152	Codeforces 1561A: Simply Strange Sort

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

7201

Codeforces 1574A: Regular Bracket Sequences

7200

Codeforces 1573B: Swaps

7199

Codeforces 1573A: Countdown

7198

Codeforces 1572F: Stations

7197

Codeforces 1572E: Polygon

7196