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)
9801	AtCoder ABC212: A. Alloy
9800	AtCoder ABC211: F. Rectilinear Polygons
9799	AtCoder ABC211: E. Red Polyomino
9798	AtCoder ABC211: D. Number of Shortest paths
9797	AtCoder ABC211: C. chokudai
9796	AtCoder ABC211: B. Cycle Hit
9795	AtCoder ABC211: A. Blood Pressure
9794	AtCoder ABC210: F. Coprime Solitaire
9793	AtCoder ABC210: E. Ring MST
9792	AtCoder ABC210: D. National Railway
9791	AtCoder ABC210: C. Colorful Candies
9790	AtCoder ABC210: B. Bouzu Mekuri
9789	AtCoder ABC210: A. Cabbages
9788	AtCoder ABC209: F. Deforestation
9787	AtCoder ABC209: E. Shiritori
9786	AtCoder ABC209: D. Collision
9785	AtCoder ABC209: C. Not Equal
9784	AtCoder ABC209: B. Can you buy them all?
9783	AtCoder ABC209: A. Counting
9782	AtCoder ABC208: F. Cumulative Sum
9781	AtCoder ABC208: E. Digit Products
9780	AtCoder ABC208: D. Shortest Path Queries 2
9779	AtCoder ABC208: C. Fair Candy Distribution
9778	AtCoder ABC208: B. Factorial Yen Coin
9777	AtCoder ABC208: A. Rolling Dice
9776	AtCoder ABC207: F. Tree Patrolling
9775	AtCoder ABC207: E. Mod i
9774	AtCoder ABC207: D. Congruence Points
9773	AtCoder ABC207: C. Many Segments
9772	AtCoder ABC207: B. Hydrate
9771	AtCoder ABC207: A. Repression
9770	AtCoder ABC206: F. Interval Game 2
9769	AtCoder ABC206: E. Divide Both
9768	AtCoder ABC206: D. KAIBUNsyo
9767	AtCoder ABC206: C. Swappable
9766	AtCoder ABC206: B. Savings
9765	AtCoder ABC206: A. Maxi-Buying
9764	AtCoder ABC205: F. Grid and Tokens
9763	AtCoder ABC205: E. White and Black Balls
9762	AtCoder ABC205: D. Kth Excluded
9761	AtCoder ABC205: C. POW
9760	AtCoder ABC205: B. Permutation Check
9759	AtCoder ABC205: A. kcal
9758	AtCoder ABC204: F. Hanjo 2
9757	AtCoder ABC204: E. Rush Hour 2
9756	AtCoder ABC204: D. Cooking
9755	AtCoder ABC204: C. Tour
9754	AtCoder ABC204: B. Nuts
9753	AtCoder ABC204: A. Rock-paper-scissors
9752	AtCoder ABC203: F. Weed

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

9801

AtCoder ABC212: A. Alloy

9800

AtCoder ABC211: F. Rectilinear Polygons

9799

AtCoder ABC211: E. Red Polyomino

9798

AtCoder ABC211: D. Number of Shortest paths

9797

AtCoder ABC211: C. chokudai

9796