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)
2351	Codeforces 550D: Regular Bridge
2350	Codeforces 550C: Divisibility by Eight
2349	Codeforces 550B: Preparing Olympiad
2348	Codeforces 550A: Two Substrings
2347	Codeforces 549H: Degenerate Matrix
2346	Codeforces 549G: Happy Line
2345	Codeforces 549F: Yura and Developers
2344	Codeforces 549E: Sasha Circle
2343	Codeforces 549D: Haar Features
2342	Codeforces 549C: The Game Of Parity
2341	Codeforces 549B: Looksery Party
2340	Codeforces 549A: Face Detection
2339	Codeforces 548B: Mike and Fun
2338	Codeforces 548A: Mike and Fax
2337	Codeforces 547E: Mike and Friends
2336	Codeforces 547D: Mike and Fish
2335	Codeforces 547C: Mike and Foam
2334	Codeforces 547B: Mike and Feet
2333	Codeforces 547A: Mike and Frog
2332	Codeforces 546E: Soldier and Traveling
2331	Codeforces 546D: Soldier and Number Game
2330	Codeforces 546C: Soldier and Cards
2329	Codeforces 546B: Soldier and Badges
2328	Codeforces 546A: Soldier and Bananas
2327	Codeforces 545E: Paths and Trees
2326	Codeforces 545D: Queue
2325	Codeforces 545C: Woodcutters
2324	Codeforces 545B: Equidistant String
2323	Codeforces 545A: Toy Cars
2322	Codeforces 544B: Sea and Islands
2321	Codeforces 544A: Set of Strings
2320	Codeforces 543E: Listening to Music
2319	Codeforces 543D: Road Improvement
2318	Codeforces 543C: Remembering Strings
2317	Codeforces 543B: Destroying Roads
2316	Codeforces 543A: Writing Code
2315	Codeforces 542F: Quest
2314	Codeforces 542E: Playing on Graph
2313	Codeforces 542D: Superhero's Job
2312	Codeforces 542C: Idempotent functions
2311	Codeforces 542B: Duck Hunt
2310	Codeforces 542A: Place Your Ad Here
2309	Codeforces 540E: Infinite Inversions
2308	Codeforces 540D: Bad Luck Island
2307	Codeforces 540C: Ice Cave
2306	Codeforces 540B: School Marks
2305	Codeforces 540A: Combination Lock
2304	Codeforces 538H: Summer Dichotomy
2303	Codeforces 538G: Berserk Robot
2302	Codeforces 538F: A Heap of Heaps

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

2351

Codeforces 550D: Regular Bridge

2350

Codeforces 550C: Divisibility by Eight

2349

Codeforces 550B: Preparing Olympiad

2348

Codeforces 550A: Two Substrings

2347

Codeforces 549H: Degenerate Matrix

2346