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)
7251	Codeforces 1582B: Luntik and Subsequences
7250	Codeforces 1582A: Luntik and Concerts
7249	Codeforces 1581B: Diameter of Graph
7248	Codeforces 1581A: CQXYM Count Permutations
7247	Codeforces 1580F: Problems for Codeforces
7246	Codeforces 1580E: Railway Construction
7245	Codeforces 1580D: Subsequence
7244	Codeforces 1580C: Train Maintenance
7243	Codeforces 1580B: Mathematics Curriculum
7242	Codeforces 1580A: Portal
7241	Codeforces 1579G: Minimal Coverage
7240	Codeforces 1579F: Array Stabilization (AND version)
7239	Codeforces 1579E2: Array Optimization by Deque
7238	Codeforces 1579E1: Permutation Minimization by Deque
7237	Codeforces 1579D: Productive Meeting
7236	Codeforces 1579C: Ticks
7235	Codeforces 1579B: Shifting Sort
7234	Codeforces 1579A: Casimir's String Solitaire
7233	Codeforces 1578M: The Mind
7232	Codeforces 1578L: Labyrinth
7231	Codeforces 1578K: Kingdom of Islands
7230	Codeforces 1578J: Just Kingdom
7229	Codeforces 1578I: Interactive Rays
7228	Codeforces 1578H: Higher Order Functions
7227	Codeforces 1578G: Game of Chance
7226	Codeforces 1578F: Framing Pictures
7225	Codeforces 1578E: Easy Scheduling
7224	Codeforces 1578D: Dragon Curve
7223	Codeforces 1578C: Cactus Lady and her Cing
7222	Codeforces 1578B: Building Forest Trails
7221	Codeforces 1578A: Anti-Tetris
7220	Codeforces 1576A: Communication Routing Challenge
7219	Codeforces 1575M: Managing Telephone Poles
7218	Codeforces 1575L: Longest Array Deconstruction
7217	Codeforces 1575K: Knitting Batik
7216	Codeforces 1575J: Jeopardy of Dropped Balls
7215	Codeforces 1575I: Illusions of the Desert
7214	Codeforces 1575H: Holiday Wall Ornaments
7213	Codeforces 1575G: GCD Festival
7212	Codeforces 1575F: Finding Expected Value
7211	Codeforces 1575E: Eye-Pleasing City Park Tour
7210	Codeforces 1575D: Divisible by Twenty-Five
7209	Codeforces 1575C: Cyclic Sum
7208	Codeforces 1575B: Building an Amusement Park
7207	Codeforces 1575A: Another Sorting Problem
7206	Codeforces 1574F: Occurrences
7205	Codeforces 1574E: Coloring
7204	Codeforces 1574D: The Strongest Build
7203	Codeforces 1574C: Slay the Dragon
7202	Codeforces 1574B: Combinatorics Homework

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

7251

Codeforces 1582B: Luntik and Subsequences

7250

Codeforces 1582A: Luntik and Concerts

7249

Codeforces 1581B: Diameter of Graph

7248

Codeforces 1581A: CQXYM Count Permutations

7247

Codeforces 1580F: Problems for Codeforces

7246