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)
801	Codeforces 171C: A Piece of Cake
800	Codeforces 171B: Star
799	Codeforces 171A: Mysterious numbers - 1
798	Codeforces 169B: Replacing Digits
797	Codeforces 169A: Chores
796	Codeforces 168B: Wizards and Minimal Spell
795	Codeforces 168A: Wizards and Demonstration
794	Codeforces 167E: Wizards and Bets
793	Codeforces 167D: Wizards and Roads
792	Codeforces 167C: Wizards and Numbers
791	Codeforces 167B: Wizards and Huge Prize
790	Codeforces 167A: Wizards and Trolleybuses
789	Codeforces 166E: Tetrahedron
788	Codeforces 166D: Shoe Store
787	Codeforces 166C: Median
786	Codeforces 166B: Polygons
785	Codeforces 166A: Rank List
784	Codeforces 165E: Compatible Numbers
783	Codeforces 165D: Beard Graph
782	Codeforces 165C: Another Problem on Strings
781	Codeforces 165B: Burning Midnight Oil
780	Codeforces 165A: Supercentral Point
779	Codeforces 164E: Polycarpus and Tasks
778	Codeforces 164D: Minimum Diameter
777	Codeforces 164C: Machine Programming
776	Codeforces 164B: Ancient Berland Hieroglyphs
775	Codeforces 164A: Variable, or There and Back Again
774	Codeforces 163E: e-Government
773	Codeforces 163D: Large Refrigerator
772	Codeforces 163C: Conveyor
771	Codeforces 163B: Lemmings
770	Codeforces 163A: Substring and Subsequence
769	Codeforces 162J: Brackets
768	Codeforces 162I: Truncatable primes
767	Codeforces 162H: Alternating case
766	Codeforces 162G: Non-decimal sum
765	Codeforces 162F: Factorial zeros
764	Codeforces 162E: HQ9+
763	Codeforces 162D: Remove digits
762	Codeforces 162C: Prime factorization
761	Codeforces 162B: Binary notation
760	Codeforces 162A: Pentagonal numbers
759	Codeforces 161E: Polycarpus the Safecracker
758	Codeforces 161D: Distance in Tree
757	Codeforces 161C: Abracadabra
756	Codeforces 161B: Discounts
755	Codeforces 161A: Dress'em in Vests!
754	Codeforces 160E: Buses and People
753	Codeforces 160D: Edges in MST
752	Codeforces 160C: Find Pair

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

801

Codeforces 171C: A Piece of Cake

800

Codeforces 171B: Star

799

Codeforces 171A: Mysterious numbers - 1

798

Codeforces 169B: Replacing Digits

797

Codeforces 169A: Chores

796