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)
11701	AtCoder ARC142: A. Reverse and Minimize
11700	AtCoder ARC141: F. Well-defined Abbreviation
11699	AtCoder ARC141: E. Sliding Edge on Torus
11698	AtCoder ARC141: D. Non-divisible Set
11697	AtCoder ARC141: C. Bracket and Permutation
11696	AtCoder ARC141: B. Increasing Prefix XOR
11695	AtCoder ARC141: A. Periodic Number
11694	AtCoder ARC140: F. ABS Permutation (Count ver.)
11693	AtCoder ARC140: E. Not Equal Rectangle
11692	AtCoder ARC140: D. One to One
11691	AtCoder ARC140: C. ABS Permutation (LIS ver.)
11690	AtCoder ARC140: B. Shorten ARC
11689	AtCoder ARC140: A. Right String
11688	AtCoder ARC139: F. Many Xor Optimization Problems
11687	AtCoder ARC139: E. Wazir
11686	AtCoder ARC139: D. Priority Queue 2
11685	AtCoder ARC139: C. One Three Nine
11684	AtCoder ARC139: B. Make N
11683	AtCoder ARC139: A. Trailing Zeros
11682	AtCoder ARC138: F. KD Tree
11681	AtCoder ARC138: E. Decreasing Subsequence
11680	AtCoder ARC138: D. Differ by K bits
11679	AtCoder ARC138: C. Rotate and Play Game
11678	AtCoder ARC138: B. 01 Generation
11677	AtCoder ARC138: A. Larger Score
11676	AtCoder ARC137: F. Overlaps
11675	AtCoder ARC137: E. Bakery
11674	AtCoder ARC137: D. Prefix XORs
11673	AtCoder ARC137: C. Distinct Numbers
11672	AtCoder ARC137: B. Count 1's
11671	AtCoder ARC137: A. Coprime Pair
11670	AtCoder ARC136: F. Flip Cells
11669	AtCoder ARC136: E. Non-coprime DAG
11668	AtCoder ARC136: D. Without Carry
11667	AtCoder ARC136: C. Circular Addition
11666	AtCoder ARC136: B. Triple Shift
11665	AtCoder ARC136: A. A ↔ BB
11664	AtCoder ARC135: F. Delete 1, 4, 7, ...
11663	AtCoder ARC135: E. Sequence of Multiples
11662	AtCoder ARC135: D. Add to Square
11661	AtCoder ARC135: C. XOR to All
11660	AtCoder ARC135: B. Sum of Three Terms
11659	AtCoder ARC135: A. Floor, Ceil - Decomposition
11658	AtCoder ARC134: F. Flipping Coins
11657	AtCoder ARC134: E. Modulo Nim
11656	AtCoder ARC134: D. Concatenate Subsequences
11655	AtCoder ARC134: C. The Majority
11654	AtCoder ARC134: B. Reserve or Reverse
11653	AtCoder ARC134: A. Bridge and Sheets
11652	AtCoder ARC133: F. Random Transition

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

11701

AtCoder ARC142: A. Reverse and Minimize

11700

AtCoder ARC141: F. Well-defined Abbreviation

11699

AtCoder ARC141: E. Sliding Edge on Torus

11698

AtCoder ARC141: D. Non-divisible Set

11697

AtCoder ARC141: C. Bracket and Permutation

11696