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Over 20,000 problems available: AMC 8/10/12 and AIME problems from 2010-2024; USAJMO/USAMO problems from 2002-2024; USACO problems from 2014 to 2024 (all divisions); all Codeforces, AtCoder and DMOJ problems. If you leave the search field blank, it returns all problems with the specified type.

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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)
10255 AtCoder ABC268: G. Random Student ID
10254 AtCoder ABC268: F. Best Concatenation
10253 AtCoder ABC268: E. Chinese Restaurant (Three-Star Version)
10252 AtCoder ABC268: D. Unique Username
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
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