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)
2301	Codeforces 538E: Demiurges Play Again
2300	Codeforces 538D: Weird Chess
2299	Codeforces 538C: Tourist's Notes
2298	Codeforces 538B: Quasi Binary
2297	Codeforces 538A: Cutting Banner
2296	Codeforces 536E: Tavas on the Path
2295	Codeforces 536D: Tavas in Kansas
2294	Codeforces 535E: Tavas and Pashmaks
2293	Codeforces 535D: Tavas and Malekas
2292	Codeforces 535C: Tavas and Karafs
2291	Codeforces 535B: Tavas and SaDDas
2290	Codeforces 535A: Tavas and Nafas
2289	Codeforces 534F: Simplified Nonogram
2288	Codeforces 534E: Berland Local Positioning System
2287	Codeforces 534D: Handshakes
2286	Codeforces 534C: Polycarpus' Dice
2285	Codeforces 534B: Covered Path
2284	Codeforces 534A: Exam
2283	Codeforces 533F: Encoding
2282	Codeforces 533E: Correcting Mistakes
2281	Codeforces 533D: Landmarks
2280	Codeforces 533C: Board Game
2279	Codeforces 533B: Work Group
2278	Codeforces 533A: Berland Miners
2277	Codeforces 530I: Different variables
2276	Codeforces 530H: Points in triangle
2275	Codeforces 530G: Levenshtein distance
2274	Codeforces 530F: Jumping frogs
2273	Codeforces 530E: Sum and product
2272	Codeforces 530D: Set subtraction
2271	Codeforces 530C: Diophantine equation
2270	Codeforces 530B: String inside out
2269	Codeforces 530A: Quadratic equation
2268	Codeforces 529B: Group Photo 2 (online mirror version)
2267	Codeforces 528E: Triangles 3000
2266	Codeforces 528D: Fuzzy Search
2265	Codeforces 527E: Data Center Drama
2264	Codeforces 527D: Clique Problem
2263	Codeforces 527C: Glass Carving
2262	Codeforces 527B: Error Correct System
2261	Codeforces 527A: Playing with Paper
2260	Codeforces 526G: Spiders Evil Plan
2259	Codeforces 526F: Pudding Monsters
2258	Codeforces 526E: Transmitting Levels
2257	Codeforces 526D: Om Nom and Necklace
2256	Codeforces 526C: Om Nom and Candies
2255	Codeforces 526B: Om Nom and Dark Park
2254	Codeforces 526A: King of Thieves
2253	Codeforces 525E: Anya and Cubes
2252	Codeforces 525D: Arthur and Walls

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

2301

Codeforces 538E: Demiurges Play Again

2300

Codeforces 538D: Weird Chess

2299

Codeforces 538C: Tourist's Notes

2298

Codeforces 538B: Quasi Binary

2297

Codeforces 538A: Cutting Banner

2296