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)
6301	Codeforces 1399E2: Weights Division (hard version)
6300	Codeforces 1399E1: Weights Division (easy version)
6299	Codeforces 1399D: Binary String To Subsequences
6298	Codeforces 1399C: Boats Competition
6297	Codeforces 1399B: Gifts Fixing
6296	Codeforces 1399A: Remove Smallest
6295	Codeforces 1398G: Running Competition
6294	Codeforces 1398F: Controversial Rounds
6293	Codeforces 1398E: Two Types of Spells
6292	Codeforces 1398D: Colored Rectangles
6291	Codeforces 1398C: Good Subarrays
6290	Codeforces 1398B: Substring Removal Game
6289	Codeforces 1398A: Bad Triangle
6288	Codeforces 1397B: Power Sequence
6287	Codeforces 1397A: Juggling Letters
6286	Codeforces 1396E: Distance Matching
6285	Codeforces 1396D: Rainbow Rectangles
6284	Codeforces 1396C: Monster Invaders
6283	Codeforces 1396B: Stoned Game
6282	Codeforces 1396A: Multiples of Length
6281	Codeforces 1395C: Boboniu and Bit Operations
6280	Codeforces 1395B: Boboniu Plays Chess
6279	Codeforces 1395A: Boboniu Likes to Color Balls
6278	Codeforces 1394E: Boboniu and Banknote Collection
6277	Codeforces 1394D: Boboniu and Jianghu
6276	Codeforces 1394C: Boboniu and String
6275	Codeforces 1394B: Boboniu Walks on Graph
6274	Codeforces 1394A: Boboniu Chats with Du
6273	Codeforces 1393E2: Twilight and Ancient Scroll (harder version)
6272	Codeforces 1393E1: Twilight and Ancient Scroll (easier version)
6271	Codeforces 1393D: Rarity and New Dress
6270	Codeforces 1393C: Pinkie Pie Eats Patty-cakes
6269	Codeforces 1393B: Applejack and Storages
6268	Codeforces 1393A: Rainbow Dash, Fluttershy and Chess Coloring
6267	Codeforces 1392I: Kevin and Grid
6266	Codeforces 1392H: ZS Shuffles Cards
6265	Codeforces 1392G: Omkar and Pies
6264	Codeforces 1392F: Omkar and Landslide
6263	Codeforces 1392E: Omkar and Duck
6262	Codeforces 1392D: Omkar and Bed Wars
6261	Codeforces 1392C: Omkar and Waterslide
6260	Codeforces 1392B: Omkar and Infinity Clock
6259	Codeforces 1392A: Omkar and Password
6258	Codeforces 1391E: Pairs of Pairs
6257	Codeforces 1391D: 505
6256	Codeforces 1391C: Cyclic Permutations
6255	Codeforces 1391B: Fix You
6254	Codeforces 1391A: Suborrays
6253	Codeforces 1389G: Directing Edges
6252	Codeforces 1389F: Bicolored Segments

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

6301

Codeforces 1399E2: Weights Division (hard version)

6300

Codeforces 1399E1: Weights Division (easy version)

6299

Codeforces 1399D: Binary String To Subsequences

6298

Codeforces 1399C: Boats Competition

6297

Codeforces 1399B: Gifts Fixing

6296