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)
4051	Codeforces 949A: Zebras
4050	Codeforces 948A: Protect Sheep
4049	Codeforces 946G: Almost Increasing Array
4048	Codeforces 946F: Fibonacci String Subsequences
4047	Codeforces 946E: Largest Beautiful Number
4046	Codeforces 946D: Timetable
4045	Codeforces 946C: String Transformation
4044	Codeforces 946B: Weird Subtraction Process
4043	Codeforces 946A: Partition
4042	Codeforces 940F: Machine Learning
4041	Codeforces 940E: Cashback
4040	Codeforces 940D: Alena And The Heater
4039	Codeforces 940C: Phone Numbers
4038	Codeforces 940B: Our Tanya is Crying Out Loud
4037	Codeforces 940A: Points on the line
4036	Codeforces 939F: Cutlet
4035	Codeforces 939E: Maximize!
4034	Codeforces 939D: Love Rescue
4033	Codeforces 939C: Convenient For Everybody
4032	Codeforces 939B: Hamster Farm
4031	Codeforces 939A: Love Triangle
4030	Codeforces 938G: Shortest Path Queries
4029	Codeforces 938F: Erasing Substrings
4028	Codeforces 938E: Max History
4027	Codeforces 938D: Buy a Ticket
4026	Codeforces 938C: Constructing Tests
4025	Codeforces 938B: Run For Your Prize
4024	Codeforces 938A: Word Correction
4023	Codeforces 937B: Vile Grasshoppers
4022	Codeforces 937A: Olympiad
4021	Codeforces 936E: Iqea
4020	Codeforces 936D: World of Tank
4019	Codeforces 936C: Lock Puzzle
4018	Codeforces 936B: Sleepy Game
4017	Codeforces 936A: Save Energy!
4016	Codeforces 935F: Fafa and Array
4015	Codeforces 935E: Fafa and Ancient Mathematics
4014	Codeforces 935D: Fafa and Ancient Alphabet
4013	Codeforces 935C: Fifa and Fafa
4012	Codeforces 935B: Fafa and the Gates
4011	Codeforces 935A: Fafa and his Company
4010	Codeforces 934B: A Prosperous Lot
4009	Codeforces 934A: A Compatible Pair
4008	Codeforces 933E: A Preponderant Reunion
4007	Codeforces 933D: A Creative Cutout
4006	Codeforces 933C: A Colourful Prospect
4005	Codeforces 933B: A Determined Cleanup
4004	Codeforces 933A: A Twisty Movement
4003	Codeforces 932G: Palindrome Partition
4002	Codeforces 932F: Escape Through Leaf

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

4051

Codeforces 949A: Zebras

4050

Codeforces 948A: Protect Sheep

4049

Codeforces 946G: Almost Increasing Array

4048

Codeforces 946F: Fibonacci String Subsequences

4047

Codeforces 946E: Largest Beautiful Number

4046