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)
2451	Codeforces 578C: Weakness and Poorness
2450	Codeforces 578B: "Or" Game
2449	Codeforces 578A: A Problem about Polyline
2448	Codeforces 577B: Modulo Sum
2447	Codeforces 577A: Multiplication Table
2446	Codeforces 576E: Painting Edges
2445	Codeforces 576D: Flights for Regular Customers
2444	Codeforces 576C: Points on Plane
2443	Codeforces 576B: Invariance of Tree
2442	Codeforces 576A: Vasya and Petya's Game
2441	Codeforces 575I: Robots protection
2440	Codeforces 575H: Bots
2439	Codeforces 575G: Run for beer
2438	Codeforces 575F: Bulbo
2437	Codeforces 575E: Spectator Riots
2436	Codeforces 575D: Tablecity
2435	Codeforces 575C: Party
2434	Codeforces 575B: Bribes
2433	Codeforces 575A: Fibonotci
2432	Codeforces 574B: Bear and Three Musketeers
2431	Codeforces 574A: Bear and Elections
2430	Codeforces 573E: Bear and Bowling
2429	Codeforces 573D: Bear and Cavalry
2428	Codeforces 573C: Bear and Drawing
2427	Codeforces 573B: Bear and Blocks
2426	Codeforces 573A: Bear and Poker
2425	Codeforces 572B: Order Book
2424	Codeforces 572A: Arrays
2423	Codeforces 571E: Geometric Progressions
2422	Codeforces 571D: Campus
2421	Codeforces 571C: CNF 2
2420	Codeforces 571B: Minimization
2419	Codeforces 571A: Lengthening Sticks
2418	Codeforces 570E: Pig and Palindromes
2417	Codeforces 570D: Tree Requests
2416	Codeforces 570C: Replacement
2415	Codeforces 570B: Simple Game
2414	Codeforces 570A: Elections
2413	Codeforces 569B: Inventory
2412	Codeforces 569A: Music
2411	Codeforces 568E: Longest Increasing Subsequence
2410	Codeforces 568D: Sign Posts
2409	Codeforces 568C: New Language
2408	Codeforces 568B: Symmetric and Transitive
2407	Codeforces 568A: Primes or Palindromes?
2406	Codeforces 567F: Mausoleum
2405	Codeforces 567E: President and Roads
2404	Codeforces 567D: One-Dimensional Battle Ships
2403	Codeforces 567C: Geometric Progression
2402	Codeforces 567B: Berland National Library

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

2451

Codeforces 578C: Weakness and Poorness

2450

Codeforces 578B: "Or" Game

2449

Codeforces 578A: A Problem about Polyline

2448

Codeforces 577B: Modulo Sum

2447

Codeforces 577A: Multiplication Table

2446