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)
10401	AtCoder ABC287: A. Majority
10400	AtCoder ABC286: Ex. Don't Swim
10399	AtCoder ABC286: G. Unique Walk
10398	AtCoder ABC286: F. Guess The Number 2
10397	AtCoder ABC286: E. Souvenir
10396	AtCoder ABC286: D. Money in Hand
10395	AtCoder ABC286: C. Rotate and Palindrome
10394	AtCoder ABC286: B. Cat
10393	AtCoder ABC286: A. Range Swap
10392	AtCoder ABC285: Ex. Avoid Square Number
10391	AtCoder ABC285: G. Tatami
10390	AtCoder ABC285: F. Substring of Sorted String
10389	AtCoder ABC285: E. Work or Rest
10388	AtCoder ABC285: D. Change Usernames
10387	AtCoder ABC285: C. abc285_brutmhyhiizp
10386	AtCoder ABC285: B. Longest Uncommon Prefix
10385	AtCoder ABC285: A. Edge Checker 2
10384	AtCoder ABC284: Ex. Count Unlabeled Graphs
10383	AtCoder ABC284: G. Only Once
10382	AtCoder ABC284: F. ABCBAC
10381	AtCoder ABC284: E. Count Simple Paths
10380	AtCoder ABC284: D. Happy New Year 2023
10379	AtCoder ABC284: C. Count Connected Components
10378	AtCoder ABC284: B. Multi Test Cases
10377	AtCoder ABC284: A. Sequence of Strings
10376	AtCoder ABC283: Ex. Popcount Sum
10375	AtCoder ABC283: G. Partial Xor Enumeration
10374	AtCoder ABC283: F. Permutation Distance
10373	AtCoder ABC283: E. Don't Isolate Elements
10372	AtCoder ABC283: D. Scope
10371	AtCoder ABC283: C. Cash Register
10370	AtCoder ABC283: B. First Query Problem
10369	AtCoder ABC283: A. Power
10368	AtCoder ABC282: Ex. Min + Sum
10367	AtCoder ABC282: G. Similar Permutation
10366	AtCoder ABC282: F. Union of Two Sets
10365	AtCoder ABC282: E. Choose Two and Eat One
10364	AtCoder ABC282: D. Make Bipartite 2
10363	AtCoder ABC282: C. String Delimiter
10362	AtCoder ABC282: B. Let's Get a Perfect Score
10361	AtCoder ABC282: A. Generalized ABC
10360	AtCoder ABC281: Ex. Alchemy
10359	AtCoder ABC281: G. Farthest City
10358	AtCoder ABC281: F. Xor Minimization
10357	AtCoder ABC281: E. Least Elements
10356	AtCoder ABC281: D. Max Multiple
10355	AtCoder ABC281: C. Circular Playlist
10354	AtCoder ABC281: B. Sandwich Number
10353	AtCoder ABC281: A. Count Down
10352	AtCoder ABC280: Ex. Substring Sort

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

10401

AtCoder ABC287: A. Majority

10400

AtCoder ABC286: Ex. Don't Swim

10399

AtCoder ABC286: G. Unique Walk

10398

AtCoder ABC286: F. Guess The Number 2

10397

AtCoder ABC286: E. Souvenir

10396