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)
901	Codeforces 189A: Cut Ribbon
900	Codeforces 188H: Stack
899	Codeforces 188G: Array Sorting
898	Codeforces 188F: Binary Notation
897	Codeforces 188E: HQ9+
896	Codeforces 188D: Asterisks
895	Codeforces 188C: LCM
894	Codeforces 188B: A + Reverse B
893	Codeforces 188A: Hexagonal Numbers
892	Codeforces 187E: Heaven Tour
891	Codeforces 187D: BRT Contract
890	Codeforces 187C: Weak Memory
889	Codeforces 187B: AlgoRace
888	Codeforces 187A: Permutations
887	Codeforces 186B: Growing Mushrooms
886	Codeforces 186A: Comparing Strings
885	Codeforces 185E: Soap Time! - 2
884	Codeforces 185D: Visit of the Great
883	Codeforces 185C: Clever Fat Rat
882	Codeforces 185B: Mushroom Scientists
881	Codeforces 185A: Plant
880	Codeforces 183E: Candy Shop
879	Codeforces 183D: T-shirt
878	Codeforces 183C: Cyclic Coloring
877	Codeforces 183B: Zoo
876	Codeforces 183A: Headquarters
875	Codeforces 182E: Wooden Fence
874	Codeforces 182D: Common Divisors
873	Codeforces 182C: Optimal Sum
872	Codeforces 182B: Vasya's Calendar
871	Codeforces 182A: Battlefield
870	Codeforces 181B: Number of Triplets
869	Codeforces 181A: Series of Crimes
868	Codeforces 180F: Mathematical Analysis Rocks!
867	Codeforces 180E: Cubes
866	Codeforces 180D: Name
865	Codeforces 180C: Letter
864	Codeforces 180B: Divisibility Rules
863	Codeforces 180A: Defragmentation
862	Codeforces 178F3: Representative Sampling
861	Codeforces 178F2: Representative Sampling
860	Codeforces 178F1: Representative Sampling
859	Codeforces 178E3: The Beaver's Problem - 2
858	Codeforces 178E2: The Beaver's Problem - 2
857	Codeforces 178E1: The Beaver's Problem - 2
856	Codeforces 178D3: Magic Squares
855	Codeforces 178D2: Magic Squares
854	Codeforces 178D1: Magic Squares
853	Codeforces 178C3: Smart Beaver and Resolving Collisions
852	Codeforces 178C2: Smart Beaver and Resolving Collisions

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

901

Codeforces 189A: Cut Ribbon

900

Codeforces 188H: Stack

899

Codeforces 188G: Array Sorting

898

Codeforces 188F: Binary Notation

897

Codeforces 188E: HQ9+

896