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)
14951	AtCoder XMASCONTEST2015: F. FILO Sort
14950	AtCoder XMASCONTEST2015: E. Esolang?
14949	AtCoder XMASCONTEST2015: D. Destroy the Duplicated Poem
14948	AtCoder XMASCONTEST2015: C. Colored Tiles
14947	AtCoder XMASCONTEST2015: B. Broken Christmas Tree
14946	AtCoder XMASCONTEST2015: A. Accumulation
14945	AtCoder XMASCON22: H. Happy Game
14944	AtCoder XMASCON22: G. Generator SAT
14943	AtCoder XMASCON22: F. Fast as Fast as Ryser
14942	AtCoder XMASCON22: E. Educational Statement
14941	AtCoder XMASCON22: D. Dichotomy
14940	AtCoder XMASCON22: C. Conditional Swap
14939	AtCoder XMASCON22: B. Battle Solving
14938	AtCoder XMASCON22: A. Arte Del Latte
14937	AtCoder XMASCON21: I. Interactive Moles
14936	AtCoder XMASCON21: H. Homework from Zhejiang
14935	AtCoder XMASCON21: G. Game of Distinction
14934	AtCoder XMASCON21: F. Fractal and Palindrome
14933	AtCoder XMASCON21: E. E and PI
14932	AtCoder XMASCON21: D. Determinant?
14931	AtCoder XMASCON21: C. Count Me
14930	AtCoder XMASCON21: B. Bad Mood
14929	AtCoder XMASCON21: A. At Random
14928	AtCoder XMASCON20: I. Implement Me
14927	AtCoder XMASCON20: H. Hierarchical Phylogeny
14926	AtCoder XMASCON20: G. Graph Products
14925	AtCoder XMASCON20: F. Famous in Russia
14924	AtCoder XMASCON20: E. Eternal Dice
14923	AtCoder XMASCON20: D. Determinant
14922	AtCoder XMASCON20: C. Candies Candidates
14921	AtCoder XMASCON20: B. Beterminant
14920	AtCoder XMASCON20: A. Additive-Subtractive Stamps
14919	AtCoder XMASCON19: L. Signboard 2
14918	AtCoder XMASCON19: K. Set of Trees
14917	AtCoder XMASCON19: J. Sub-Post Correspondence Problem
14916	AtCoder XMASCON19: I. Stamps 4
14915	AtCoder XMASCON19: H. Stamps 3
14914	AtCoder XMASCON19: G. Stamps 2
14913	AtCoder XMASCON19: F. Stamps 1
14912	AtCoder XMASCON19: E. Sum of f(n)
14911	AtCoder XMASCON19: D. Sum of (-1)^f(n)
14910	AtCoder XMASCON19: C. Sokoban
14909	AtCoder XMASCON19: B. Set of Integers
14908	AtCoder XMASCON19: A. Signboard 1
14907	AtCoder XMASCON18: J. Japanese Exponentation
14906	AtCoder XMASCON18: I. Interesting Equation
14905	AtCoder XMASCON18: H. Hello, Xmas Contest 2018
14904	AtCoder XMASCON18: G. Good Game
14903	AtCoder XMASCON18: F. Fluffy Fox
14902	AtCoder XMASCON18: E. Exclusive☆OR

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

14951

AtCoder XMASCONTEST2015: F. FILO Sort

14950

AtCoder XMASCONTEST2015: E. Esolang?

14949

AtCoder XMASCONTEST2015: D. Destroy the Duplicated Poem

14948

AtCoder XMASCONTEST2015: C. Colored Tiles

14947

AtCoder XMASCONTEST2015: B. Broken Christmas Tree

14946