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)
10251	AtCoder ABC268: C. Chinese Restaurant
10250	AtCoder ABC268: B. Prefix?
10249	AtCoder ABC268: A. Five Integers
10248	AtCoder ABC267: Ex. Odd Sum
10247	AtCoder ABC267: G. Increasing K Times
10246	AtCoder ABC267: F. Exactly K Steps
10245	AtCoder ABC267: E. Erasing Vertices 2
10244	AtCoder ABC267: D. Index × A(Not Continuous ver.)
10243	AtCoder ABC267: C. Index × A(Continuous ver.)
10242	AtCoder ABC267: B. Split?
10241	AtCoder ABC267: A. Saturday
10240	AtCoder ABC266: Ex. Snuke Panic (2D)
10239	AtCoder ABC266: G. Yet Another RGB Sequence
10238	AtCoder ABC266: F. Well-defined Path Queries on a Namori
10237	AtCoder ABC266: E. Throwing the Die
10236	AtCoder ABC266: D. Snuke Panic (1D)
10235	AtCoder ABC266: C. Convex Quadrilateral
10234	AtCoder ABC266: B. Modulo Number
10233	AtCoder ABC266: A. Middle Letter
10232	AtCoder ABC265: Ex. No-capture Lance Game
10231	AtCoder ABC265: G. 012 Inversion
10230	AtCoder ABC265: F. Manhattan Cafe
10229	AtCoder ABC265: E. Warp
10228	AtCoder ABC265: D. Iroha and Haiku (New ABC Edition)
10227	AtCoder ABC265: C. Belt Conveyor
10226	AtCoder ABC265: B. Explore
10225	AtCoder ABC265: A. Apple
10224	AtCoder ABC264: Ex. Perfect Binary Tree
10223	AtCoder ABC264: G. String Fair
10222	AtCoder ABC264: F. Monochromatic Path
10221	AtCoder ABC264: E. Blackout 2
10220	AtCoder ABC264: D. "redocta".swap(i,i+1)
10219	AtCoder ABC264: C. Matrix Reducing
10218	AtCoder ABC264: B. Nice Grid
10217	AtCoder ABC264: A. "atcoder".substr()
10216	AtCoder ABC263: Ex. Intersection 2
10215	AtCoder ABC263: G. Erasing Prime Pairs
10214	AtCoder ABC263: F. Tournament
10213	AtCoder ABC263: E. Sugoroku 3
10212	AtCoder ABC263: D. Left Right Operation
10211	AtCoder ABC263: C. Monotonically Increasing
10210	AtCoder ABC263: B. Ancestor
10209	AtCoder ABC263: A. Full House
10208	AtCoder ABC262: Ex. Max Limited Sequence
10207	AtCoder ABC262: G. LIS with Stack
10206	AtCoder ABC262: F. Erase and Rotate
10205	AtCoder ABC262: E. Red and Blue Graph
10204	AtCoder ABC262: D. I Hate Non-integer Number
10203	AtCoder ABC262: C. Min Max Pair
10202	AtCoder ABC262: B. Triangle (Easier)

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

10251

AtCoder ABC268: C. Chinese Restaurant

10250

AtCoder ABC268: B. Prefix?

10249

AtCoder ABC268: A. Five Integers

10248

AtCoder ABC267: Ex. Odd Sum

10247

AtCoder ABC267: G. Increasing K Times

10246