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)
8201	Codeforces 1753C: Wish I Knew How to Sort
8200	Codeforces 1753B: Factorial Divisibility
8199	Codeforces 1753A2: Make Nonzero Sum (hard version)
8198	Codeforces 1753A1: Make Nonzero Sum (easy version)
8197	Codeforces 1750H: BinaryStringForces
8196	Codeforces 1750G: Doping
8195	Codeforces 1750F: Majority
8194	Codeforces 1750E: Bracket Cost
8193	Codeforces 1750D: Count GCD
8192	Codeforces 1750C: Complementary XOR
8191	Codeforces 1750B: Maximum Substring
8190	Codeforces 1750A: Indirect Sort
8189	Codeforces 1749F: Distance to the Path
8188	Codeforces 1749E: Cactus Wall
8187	Codeforces 1749D: Counting Arrays
8186	Codeforces 1749C: Number Game
8185	Codeforces 1749B: Death's Blessing
8184	Codeforces 1749A: Cowardly Rooks
8183	Codeforces 1748F: Circular Xor Reversal
8182	Codeforces 1748E: Yet Another Array Counting Problem
8181	Codeforces 1748D: ConstructOR
8180	Codeforces 1748C: Zero-Sum Prefixes
8179	Codeforces 1748B: Diverse Substrings
8178	Codeforces 1748A: The Ultimate Square
8177	Codeforces 1747E: List Generation
8176	Codeforces 1747D: Yet Another Problem
8175	Codeforces 1747C: Swap Game
8174	Codeforces 1747B: BAN BAN
8173	Codeforces 1747A: Two Groups
8172	Codeforces 1746G: Olympiad Training
8171	Codeforces 1746F: Kazaee
8170	Codeforces 1746E2: Joking (Hard Version)
8169	Codeforces 1746E1: Joking (Easy Version)
8168	Codeforces 1746D: Paths on the Tree
8167	Codeforces 1746C: Permutation Operations
8166	Codeforces 1746B: Rebellion
8165	Codeforces 1746A: Maxmina
8164	Codeforces 1744F: MEX vs MED
8163	Codeforces 1744E2: Divisible Numbers (hard version)
8162	Codeforces 1744E1: Divisible Numbers (easy version)
8161	Codeforces 1744D: Divisibility by 2^n
8160	Codeforces 1744C: Traffic Light
8159	Codeforces 1744B: Even-Odd Increments
8158	Codeforces 1744A: Number Replacement
8157	Codeforces 1743G: Antifibonacci Cut
8156	Codeforces 1743F: Intersection and Union
8155	Codeforces 1743E: FTL
8154	Codeforces 1743D: Problem with Random Tests
8153	Codeforces 1743C: Save the Magazines
8152	Codeforces 1743B: Permutation Value

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

8201

Codeforces 1753C: Wish I Knew How to Sort

8200

Codeforces 1753B: Factorial Divisibility

8199

Codeforces 1753A2: Make Nonzero Sum (hard version)

8198

Codeforces 1753A1: Make Nonzero Sum (easy version)

8197

Codeforces 1750H: BinaryStringForces

8196