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)
10051	AtCoder ABC243: C. Collision 2
10050	AtCoder ABC243: B. Hit and Blow
10049	AtCoder ABC243: A. Shampoo
10048	AtCoder ABC242: Ex. Random Painting
10047	AtCoder ABC242: G. Range Pairing Query
10046	AtCoder ABC242: F. Black and White Rooks
10045	AtCoder ABC242: E. (∀x∀)
10044	AtCoder ABC242: D. ABC Transform
10043	AtCoder ABC242: C. 1111gal password
10042	AtCoder ABC242: B. Minimize Ordering
10041	AtCoder ABC242: A. T-shirt
10040	AtCoder ABC241: Ex. Card Deck Score
10039	AtCoder ABC241: G. Round Robin
10038	AtCoder ABC241: F. Skate
10037	AtCoder ABC241: E. Putting Candies
10036	AtCoder ABC241: D. Sequence Query
10035	AtCoder ABC241: C. Connect 6
10034	AtCoder ABC241: B. Pasta
10033	AtCoder ABC241: A. Digit Machine
10032	AtCoder ABC240: Ex. Sequence of Substrings
10031	AtCoder ABC240: G. Teleporting Takahashi
10030	AtCoder ABC240: F. Sum Sum Max
10029	AtCoder ABC240: E. Ranges on Tree
10028	AtCoder ABC240: D. Strange Balls
10027	AtCoder ABC240: C. Jumping Takahashi
10026	AtCoder ABC240: B. Count Distinct Integers
10025	AtCoder ABC240: A. Edge Checker
10024	AtCoder ABC239: Ex. Dice Product 2
10023	AtCoder ABC239: G. Builder Takahashi
10022	AtCoder ABC239: F. Construct Highway
10021	AtCoder ABC239: E. Subtree K-th Max
10020	AtCoder ABC239: D. Prime Sum Game
10019	AtCoder ABC239: C. Knight Fork
10018	AtCoder ABC239: B. Integer Division
10017	AtCoder ABC239: A. Horizon
10016	AtCoder ABC238: Ex. Removing People
10015	AtCoder ABC238: G. Cubic?
10014	AtCoder ABC238: F. Two Exams
10013	AtCoder ABC238: E. Range Sums
10012	AtCoder ABC238: D. AND and SUM
10011	AtCoder ABC238: C. digitnum
10010	AtCoder ABC238: B. Pizza
10009	AtCoder ABC238: A. Exponential or Quadratic
10008	AtCoder ABC237: Ex. Hakata
10007	AtCoder ABC237: G. Range Sort Query
10006	AtCoder ABC237: F. \|LIS\| = 3
10005	AtCoder ABC237: E. Skiing
10004	AtCoder ABC237: D. LR insertion
10003	AtCoder ABC237: C. kasaka
10002	AtCoder ABC237: B. Matrix Transposition

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

10051

AtCoder ABC243: C. Collision 2

10050

AtCoder ABC243: B. Hit and Blow

10049

AtCoder ABC243: A. Shampoo

10048

AtCoder ABC242: Ex. Random Painting

10047

AtCoder ABC242: G. Range Pairing Query

10046