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)
1401	Codeforces 315B: Sereja and Array
1400	Codeforces 315A: Sereja and Bottles
1399	Codeforces 314E: Sereja and Squares
1398	Codeforces 314D: Sereja and Straight Lines
1397	Codeforces 314C: Sereja and Subsequences
1396	Codeforces 314B: Sereja and Periods
1395	Codeforces 314A: Sereja and Contest
1394	Codeforces 313E: Ilya and Two Numbers
1393	Codeforces 313D: Ilya and Roads
1392	Codeforces 313C: Ilya and Matrix
1391	Codeforces 313B: Ilya and Queries
1390	Codeforces 313A: Ilya and Bank Account
1389	Codeforces 312B: Archer
1388	Codeforces 312A: Whose sentence is it?
1387	Codeforces 311E: Biologist
1386	Codeforces 311D: Interval Cubing
1385	Codeforces 311C: Fetch the Treasure
1384	Codeforces 311B: Cats Transport
1383	Codeforces 311A: The Closest Pair
1382	Codeforces 309E: Sheep
1381	Codeforces 309D: Tennis Rackets
1380	Codeforces 309C: Memory for Arrays
1379	Codeforces 309B: Context Advertising
1378	Codeforces 309A: Morning run
1377	Codeforces 306D: Polygon
1376	Codeforces 306C: White, Black and White Again
1375	Codeforces 306B: Optimizer
1374	Codeforces 306A: Candies
1373	Codeforces 305E: Playing with String
1372	Codeforces 305D: Olya and Graph
1371	Codeforces 305C: Ivan and Powers of Two
1370	Codeforces 305B: Continued Fractions
1369	Codeforces 305A: Strange Addition
1368	Codeforces 304B: Calendar
1367	Codeforces 304A: Pythagorean Theorem II
1366	Codeforces 303E: Random Ranking
1365	Codeforces 303D: Rotatable Number
1364	Codeforces 303C: Minimum Modular
1363	Codeforces 303B: Rectangle Puzzle II
1362	Codeforces 303A: Lucky Permutation Triple
1361	Codeforces 302B: Eugeny and Play List
1360	Codeforces 302A: Eugeny and Array
1359	Codeforces 301E: Yaroslav and Arrangements
1358	Codeforces 301D: Yaroslav and Divisors
1357	Codeforces 301C: Yaroslav and Algorithm
1356	Codeforces 301B: Yaroslav and Time
1355	Codeforces 301A: Yaroslav and Sequence
1354	Codeforces 300E: Empire Strikes Back
1353	Codeforces 300D: Painting Square
1352	Codeforces 300C: Beautiful Numbers

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

1401

Codeforces 315B: Sereja and Array

1400

Codeforces 315A: Sereja and Bottles

1399

Codeforces 314E: Sereja and Squares

1398

Codeforces 314D: Sereja and Straight Lines

1397

Codeforces 314C: Sereja and Subsequences

1396