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.

Need help searching? Click for format/examples of problems

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)
9951	AtCoder ABC230: G. GCD Permutation
9950	AtCoder ABC230: F. Predilection
9949	AtCoder ABC230: E. Fraction Floor Sum
9948	AtCoder ABC230: D. Destroyer Takahashi
9947	AtCoder ABC230: C. X drawing
9946	AtCoder ABC230: B. Triple Metre
9945	AtCoder ABC230: A. AtCoder Quiz 3
9944	AtCoder ABC229: H. Advance or Eat
9943	AtCoder ABC229: G. Longest Y
9942	AtCoder ABC229: F. Make Bipartite
9941	AtCoder ABC229: E. Graph Destruction
9940	AtCoder ABC229: D. Longest X
9939	AtCoder ABC229: C. Cheese
9938	AtCoder ABC229: B. Hard Calculation
9937	AtCoder ABC229: A. First Grid
9936	AtCoder ABC228: H. Histogram
9935	AtCoder ABC228: G. Digits on Grid
9934	AtCoder ABC228: F. Stamp Game
9933	AtCoder ABC228: E. Integer Sequence Fair
9932	AtCoder ABC228: D. Linear Probing
9931	AtCoder ABC228: C. Final Day
9930	AtCoder ABC228: B. Takahashi's Secret
9929	AtCoder ABC228: A. On and Off
9928	AtCoder ABC227: H. Eat Them All
9927	AtCoder ABC227: G. Divisors of Binomial Coefficient
9926	AtCoder ABC227: F. Treasure Hunting
9925	AtCoder ABC227: E. Swap
9924	AtCoder ABC227: D. Project Planning
9923	AtCoder ABC227: C. ABC conjecture
9922	AtCoder ABC227: B. KEYENCE building
9921	AtCoder ABC227: A. Last Card
9920	AtCoder ABC226: H. Random Kth Max
9919	AtCoder ABC226: G. The baggage
9918	AtCoder ABC226: F. Score of Permutations
9917	AtCoder ABC226: E. Just one
9916	AtCoder ABC226: D. Teleportation
9915	AtCoder ABC226: C. Martial artist
9914	AtCoder ABC226: B. Counting Arrays
9913	AtCoder ABC226: A. Round decimals
9912	AtCoder ABC225: H. Social Distance 2
9911	AtCoder ABC225: G. X
9910	AtCoder ABC225: F. String Cards
9909	AtCoder ABC225: E. 7
9908	AtCoder ABC225: D. Play Train
9907	AtCoder ABC225: C. Calendar Validator
9906	AtCoder ABC225: B. Star or Not
9905	AtCoder ABC225: A. Distinct Strings
9904	AtCoder ABC224: H. Security Camera 2
9903	AtCoder ABC224: G. Roll or Increment
9902	AtCoder ABC224: F. Problem where +s Separate Digits

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

9951

AtCoder ABC230: G. GCD Permutation

9950

AtCoder ABC230: F. Predilection

9949

AtCoder ABC230: E. Fraction Floor Sum

9948

AtCoder ABC230: D. Destroyer Takahashi

9947

AtCoder ABC230: C. X drawing

9946