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)
5451	Codeforces 1234B1: Social Network (easy version)
5450	Codeforces 1234A: Equalize Prices Again
5449	Codeforces 1231E: Middle-Out
5448	Codeforces 1231C: Increasing Matrix
5447	Codeforces 1230B: Ania and Minimizing
5446	Codeforces 1230A: Dawid and Bags of Candies
5445	Codeforces 1228F: One Node is Gone
5444	Codeforces 1228E: Another Filling the Grid
5443	Codeforces 1228D: Complete Tripartite
5442	Codeforces 1228C: Primes and Multiplication
5441	Codeforces 1228B: Filling the Grid
5440	Codeforces 1228A: Distinct Digits
5439	Codeforces 1227G: Not Same
5438	Codeforces 1227F2: Wrong Answer on test 233 (Hard Version)
5437	Codeforces 1227F1: Wrong Answer on test 233 (Easy Version)
5436	Codeforces 1227E: Arson In Berland Forest
5435	Codeforces 1227D2: Optimal Subsequences (Hard Version)
5434	Codeforces 1227D1: Optimal Subsequences (Easy Version)
5433	Codeforces 1227C: Messy
5432	Codeforces 1227B: Box
5431	Codeforces 1227A: Math Problem
5430	Codeforces 1225G: To Make 1
5429	Codeforces 1225F: Tree Factory
5428	Codeforces 1225E: Rock Is Push
5427	Codeforces 1225D: Power Products
5426	Codeforces 1225C: p-binary
5425	Codeforces 1225B2: TV Subscriptions (Hard Version)
5424	Codeforces 1225B1: TV Subscriptions (Easy Version)
5423	Codeforces 1225A: Forgetting Things
5422	Codeforces 1223G: Wooden Raft
5421	Codeforces 1223F: Stack Exterminable Arrays
5420	Codeforces 1223E: Paint the Tree
5419	Codeforces 1223D: Sequence Sorting
5418	Codeforces 1223C: Save the Nature
5417	Codeforces 1223B: Strings Equalization
5416	Codeforces 1223A: CME
5415	Codeforces 1221G: Graph And Numbers
5414	Codeforces 1221F: Choose a Square
5413	Codeforces 1221E: Game With String
5412	Codeforces 1221D: Make The Fence Great Again
5411	Codeforces 1221C: Perfect Team
5410	Codeforces 1221B: Knights
5409	Codeforces 1221A: 2048 Game
5408	Codeforces 1220G: Geolocation
5407	Codeforces 1220F: Gardener Alex
5406	Codeforces 1220E: Tourism
5405	Codeforces 1220D: Alex and Julian
5404	Codeforces 1220C: Substring Game in the Lesson
5403	Codeforces 1220B: Multiplication Table
5402	Codeforces 1220A: Cards

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

5451

Codeforces 1234B1: Social Network (easy version)

5450

Codeforces 1234A: Equalize Prices Again

5449

Codeforces 1231E: Middle-Out

5448

Codeforces 1231C: Increasing Matrix

5447

Codeforces 1230B: Ania and Minimizing

5446