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.

Need help searching? Click for format/examples of problems

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)
10201	AtCoder ABC262: A. World Cup
10200	AtCoder ABC261: Ex. Game on Graph
10199	AtCoder ABC261: G. Replace
10198	AtCoder ABC261: F. Sorting Color Balls
10197	AtCoder ABC261: E. Many Operations
10196	AtCoder ABC261: D. Flipping and Bonus
10195	AtCoder ABC261: C. NewFolder(1)
10194	AtCoder ABC261: B. Tournament Result
10193	AtCoder ABC261: A. Intersection
10192	AtCoder ABC260: Ex. Colorfulness
10191	AtCoder ABC260: G. Scalene Triangle Area
10190	AtCoder ABC260: F. Find 4-cycle
10189	AtCoder ABC260: E. At Least One
10188	AtCoder ABC260: D. Draw Your Cards
10187	AtCoder ABC260: C. Changing Jewels
10186	AtCoder ABC260: B. Better Students Are Needed!
10185	AtCoder ABC260: A. A Unique Letter
10184	AtCoder ABC259: Ex. Yet Another Path Counting
10183	AtCoder ABC259: G. Grid Card Game
10182	AtCoder ABC259: F. Select Edges
10181	AtCoder ABC259: E. LCM on Whiteboard
10180	AtCoder ABC259: D. Circumferences
10179	AtCoder ABC259: C. XX to XXX
10178	AtCoder ABC259: B. Counterclockwise Rotation
10177	AtCoder ABC259: A. Growth Record
10176	AtCoder ABC258: Ex. Odd Steps
10175	AtCoder ABC258: G. Triangle
10174	AtCoder ABC258: F. Main Street
10173	AtCoder ABC258: E. Packing Potatoes
10172	AtCoder ABC258: D. Trophy
10171	AtCoder ABC258: C. Rotation
10170	AtCoder ABC258: B. Number Box
10169	AtCoder ABC258: A. When?
10168	AtCoder ABC257: Ex. Dice Sum 2
10167	AtCoder ABC257: G. Prefix Concatenation
10166	AtCoder ABC257: F. Teleporter Setting
10165	AtCoder ABC257: E. Addition and Multiplication 2
10164	AtCoder ABC257: D. Jumping Takahashi 2
10163	AtCoder ABC257: C. Robot Takahashi
10162	AtCoder ABC257: B. 1D Pawn
10161	AtCoder ABC257: A. A to Z String 2
10160	AtCoder ABC256: Ex. I like Query Problem
10159	AtCoder ABC256: G. Black and White Stones
10158	AtCoder ABC256: F. Cumulative Cumulative Cumulative Sum
10157	AtCoder ABC256: E. Takahashi's Anguish
10156	AtCoder ABC256: D. Union of Interval
10155	AtCoder ABC256: C. Filling 3x3 array
10154	AtCoder ABC256: B. Batters
10153	AtCoder ABC256: A. 2^N
10152	AtCoder ABC255: Ex. Range Harvest Query

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

10201

AtCoder ABC262: A. World Cup

10200

AtCoder ABC261: Ex. Game on Graph

10199

AtCoder ABC261: G. Replace

10198

AtCoder ABC261: F. Sorting Color Balls

10197

AtCoder ABC261: E. Many Operations

10196