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)
1051	Codeforces 226B: Naughty Stone Piles
1050	Codeforces 226A: Flying Saucer Segments
1049	Codeforces 225E: Unsolvable
1048	Codeforces 225D: Snake
1047	Codeforces 225C: Barcode
1046	Codeforces 225B: Well-known Numbers
1045	Codeforces 225A: Dice Tower
1044	Codeforces 224B: Array
1043	Codeforces 224A: Parallelepiped
1042	Codeforces 223E: Planar Graph
1041	Codeforces 223D: Spider
1040	Codeforces 223C: Partial Sums
1039	Codeforces 223B: Two Strings
1038	Codeforces 223A: Bracket Sequence
1037	Codeforces 222E: Decoding Genome
1036	Codeforces 222D: Olympiad
1035	Codeforces 222C: Reducing Fractions
1034	Codeforces 222B: Cosmic Tables
1033	Codeforces 222A: Shooshuns and Sequence
1032	Codeforces 221B: Little Elephant and Numbers
1031	Codeforces 221A: Little Elephant and Function
1030	Codeforces 220E: Little Elephant and Inversions
1029	Codeforces 220D: Little Elephant and Triangle
1028	Codeforces 220C: Little Elephant and Shifts
1027	Codeforces 220B: Little Elephant and Array
1026	Codeforces 220A: Little Elephant and Problem
1025	Codeforces 219E: Parking Lot
1024	Codeforces 219D: Choosing Capital for Treeland
1023	Codeforces 219C: Color Stripe
1022	Codeforces 219B: Special Offer! Super Price 999 Bourles!
1021	Codeforces 219A: k-String
1020	Codeforces 218B: Airport
1019	Codeforces 218A: Mountain Scenery
1018	Codeforces 217E: Alien DNA
1017	Codeforces 217D: Bitonix' Patrol
1016	Codeforces 217C: Formurosa
1015	Codeforces 217B: Blackboard Fibonacci
1014	Codeforces 217A: Ice Skating
1013	Codeforces 216E: Martian Luck
1012	Codeforces 216D: Spider's Web
1011	Codeforces 216C: Hiring Staff
1010	Codeforces 216B: Forming Teams
1009	Codeforces 216A: Tiling with Hexagons
1008	Codeforces 215E: Periodical Numbers
1007	Codeforces 215D: Hot Days
1006	Codeforces 215C: Crosses
1005	Codeforces 215B: Olympic Medal
1004	Codeforces 215A: Bicycle Chain
1003	Codeforces 214B: Hometask
1002	Codeforces 214A: System of Equations

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

1051

Codeforces 226B: Naughty Stone Piles

1050

Codeforces 226A: Flying Saucer Segments

1049

Codeforces 225E: Unsolvable

1048

Codeforces 225D: Snake

1047

Codeforces 225C: Barcode

1046