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)
551	Codeforces 113B: Petr#
550	Codeforces 113A: Grammar Lessons
549	Codeforces 112B: Petya and Square
548	Codeforces 112A: Petya and Strings
547	Codeforces 111E: Petya and Rectangle
546	Codeforces 111D: Petya and Coloring
545	Codeforces 111C: Petya and Spiders
544	Codeforces 111B: Petya and Divisors
543	Codeforces 111A: Petya and Inequiations
542	Codeforces 110B: Lucky String
541	Codeforces 110A: Nearly Lucky Number
540	Codeforces 109E: Lucky Interval
539	Codeforces 109D: Lucky Sorting
538	Codeforces 109C: Lucky Tree
537	Codeforces 109B: Lucky Probability
536	Codeforces 109A: Lucky Sum of Digits
535	Codeforces 108B: Datatypes
534	Codeforces 108A: Palindromic Times
533	Codeforces 107E: Darts
532	Codeforces 107D: Crime Management
531	Codeforces 107C: Arrangement
530	Codeforces 107B: Basketball Team
529	Codeforces 107A: Dorm Water Supply
528	Codeforces 106E: Space Rescuers
527	Codeforces 106D: Treasure Island
526	Codeforces 106C: Buns
525	Codeforces 106B: Choosing Laptop
524	Codeforces 106A: Card Game
523	Codeforces 105E: Lift and Throw
522	Codeforces 105D: Entertaining Geodetics
521	Codeforces 105C: Item World
520	Codeforces 105B: Dark Assembly
519	Codeforces 105A: Transmigration
518	Codeforces 104A: Blackjack
517	Codeforces 103E: Buying Sets
516	Codeforces 103D: Time to Raid Cowavans
515	Codeforces 103C: Russian Roulette
514	Codeforces 103B: Cthulhu
513	Codeforces 103A: Testing Pants for Sadness
512	Codeforces 102B: Sum of Digits
511	Codeforces 102A: Clothes
510	Codeforces 101E: Candies and Stones
509	Codeforces 101D: Castle
508	Codeforces 101C: Vectors
507	Codeforces 101B: Buses
506	Codeforces 101A: Homework
505	Codeforces 100J: Interval Coloring
504	Codeforces 100I: Rotation
503	Codeforces 100H: Battleship
502	Codeforces 100G: Name the album

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

551

Codeforces 113B: Petr#

550

Codeforces 113A: Grammar Lessons

549

Codeforces 112B: Petya and Square

548

Codeforces 112A: Petya and Strings

547

Codeforces 111E: Petya and Rectangle

546