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)
1101	Codeforces 238A: Not Wool Sequences
1100	Codeforces 237E: Build String
1099	Codeforces 237D: T-decomposition
1098	Codeforces 237C: Primes on Interval
1097	Codeforces 237B: Young Table
1096	Codeforces 237A: Free Cash
1095	Codeforces 236B: Easy Number Challenge
1094	Codeforces 236A: Boy or Girl
1093	Codeforces 235E: Number Challenge
1092	Codeforces 235D: Graph Game
1091	Codeforces 235C: Cyclical Quest
1090	Codeforces 235B: Let's Play Osu!
1089	Codeforces 235A: LCM Challenge
1088	Codeforces 234H: Merging Two Decks
1087	Codeforces 234G: Practice
1086	Codeforces 234F: Fence
1085	Codeforces 234E: Champions' League
1084	Codeforces 234D: Cinema
1083	Codeforces 234C: Weather
1082	Codeforces 234B: Reading
1081	Codeforces 234A: Lefthanders and Righthanders
1080	Codeforces 233B: Non-square Equation
1079	Codeforces 233A: Perfect Permutation
1078	Codeforces 232E: Quick Tortoise
1077	Codeforces 232D: Fence
1076	Codeforces 232C: Doe Graphs
1075	Codeforces 232B: Table
1074	Codeforces 232A: Cycles
1073	Codeforces 231E: Cactus
1072	Codeforces 231D: Magic Box
1071	Codeforces 231C: To Add or Not to Add
1070	Codeforces 231B: Magic, Wizardry and Wonders
1069	Codeforces 231A: Team
1068	Codeforces 230B: T-primes
1067	Codeforces 230A: Dragons
1066	Codeforces 229E: Gifts
1065	Codeforces 229D: Towers
1064	Codeforces 229C: Triangles
1063	Codeforces 229B: Planets
1062	Codeforces 229A: Shifts
1061	Codeforces 228E: The Road to Berland is Paved With Good Intentions
1060	Codeforces 228D: Zigzag
1059	Codeforces 228C: Fractal Detector
1058	Codeforces 228B: Two Tables
1057	Codeforces 228A: Is your horseshoe on the other hoof?
1056	Codeforces 227B: Effective Approach
1055	Codeforces 227A: Where do I Turn?
1054	Codeforces 226E: Noble Knight's Path
1053	Codeforces 226D: The table
1052	Codeforces 226C: Anniversary

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

1101

Codeforces 238A: Not Wool Sequences

1100

Codeforces 237E: Build String

1099

Codeforces 237D: T-decomposition

1098

Codeforces 237C: Primes on Interval

1097

Codeforces 237B: Young Table

1096