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.

Need help searching? Click for format/examples of problems

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)
2751	Codeforces 645A: Amity Assessment
2750	Codeforces 644C: Hostname Aliases
2749	Codeforces 644B: Processing Queries
2748	Codeforces 644A: Parliament of Berland
2747	Codeforces 643G: Choosing Ads
2746	Codeforces 643F: Bears and Juice
2745	Codeforces 643E: Bear and Destroying Subtrees
2744	Codeforces 643D: Bearish Fanpages
2743	Codeforces 643C: Levels and Regions
2742	Codeforces 643B: Bear and Two Paths
2741	Codeforces 643A: Bear and Colors
2740	Codeforces 641G: Little Artem and Graph
2739	Codeforces 641F: Little Artem and 2-SAT
2738	Codeforces 641E: Little Artem and Time Machine
2737	Codeforces 641D: Little Artem and Random Variable
2736	Codeforces 641C: Little Artem and Dance
2735	Codeforces 641B: Little Artem and Matrix
2734	Codeforces 641A: Little Artem and Grasshopper
2733	Codeforces 639F: Bear and Chemistry
2732	Codeforces 639E: Bear and Paradox
2731	Codeforces 639D: Bear and Contribution
2730	Codeforces 639C: Bear and Polynomials
2729	Codeforces 639B: Bear and Forgotten Tree 3
2728	Codeforces 639A: Bear and Displayed Friends
2727	Codeforces 638D: Three-dimensional Turtle Super Computer
2726	Codeforces 638C: Road Improvement
2725	Codeforces 638B: Making Genome in Berland
2724	Codeforces 638A: Home Numbers
2723	Codeforces 637D: Running with Obstacles
2722	Codeforces 637C: Promocodes with Mistakes
2721	Codeforces 637B: Chat Order
2720	Codeforces 637A: Voting for Photos
2719	Codeforces 635A: Orchestra
2718	Codeforces 634A: Island Puzzle
2717	Codeforces 633H: Fibonacci-ish II
2716	Codeforces 633G: Yash And Trees
2715	Codeforces 633F: The Chocolate Spree
2714	Codeforces 633E: Startup Funding
2713	Codeforces 633D: Fibonacci-ish
2712	Codeforces 633C: Spy Syndrome 2
2711	Codeforces 633B: A Trivial Problem
2710	Codeforces 633A: Ebony and Ivory
2709	Codeforces 632F: Magic Matrix
2708	Codeforces 632E: Thief in a Shop
2707	Codeforces 632D: Longest Subsequence
2706	Codeforces 632C: The Smallest String Concatenation
2705	Codeforces 632B: Alice, Bob, Two Teams
2704	Codeforces 632A: Grandma Laura and Apples
2703	Codeforces 631E: Product Sum
2702	Codeforces 631D: Messenger

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

2751

Codeforces 645A: Amity Assessment

2750

Codeforces 644C: Hostname Aliases

2749

Codeforces 644B: Processing Queries

2748

Codeforces 644A: Parliament of Berland

2747

Codeforces 643G: Choosing Ads

2746