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)
10390 AtCoder ABC285: F. Substring of Sorted String
10389 AtCoder ABC285: E. Work or Rest
10388 AtCoder ABC285: D. Change Usernames
10387 AtCoder ABC285: C. abc285_brutmhyhiizp
10386 AtCoder ABC285: B. Longest Uncommon Prefix
10385 AtCoder ABC285: A. Edge Checker 2
10384 AtCoder ABC284: Ex. Count Unlabeled Graphs
10383 AtCoder ABC284: G. Only Once
10382 AtCoder ABC284: F. ABCBAC
10381 AtCoder ABC284: E. Count Simple Paths
10380 AtCoder ABC284: D. Happy New Year 2023
10379 AtCoder ABC284: C. Count Connected Components
10378 AtCoder ABC284: B. Multi Test Cases
10377 AtCoder ABC284: A. Sequence of Strings
10376 AtCoder ABC283: Ex. Popcount Sum
10375 AtCoder ABC283: G. Partial Xor Enumeration
10374 AtCoder ABC283: F. Permutation Distance
10373 AtCoder ABC283: E. Don't Isolate Elements
10372 AtCoder ABC283: D. Scope
10371 AtCoder ABC283: C. Cash Register
10370 AtCoder ABC283: B. First Query Problem
10369 AtCoder ABC283: A. Power
10368 AtCoder ABC282: Ex. Min + Sum
10367 AtCoder ABC282: G. Similar Permutation
10366 AtCoder ABC282: F. Union of Two Sets
10365 AtCoder ABC282: E. Choose Two and Eat One
10364 AtCoder ABC282: D. Make Bipartite 2
10363 AtCoder ABC282: C. String Delimiter
10362 AtCoder ABC282: B. Let's Get a Perfect Score
10361 AtCoder ABC282: A. Generalized ABC
10360 AtCoder ABC281: Ex. Alchemy
10359 AtCoder ABC281: G. Farthest City
10358 AtCoder ABC281: F. Xor Minimization
10357 AtCoder ABC281: E. Least Elements
10356 AtCoder ABC281: D. Max Multiple
10355 AtCoder ABC281: C. Circular Playlist
10354 AtCoder ABC281: B. Sandwich Number
10353 AtCoder ABC281: A. Count Down
10352 AtCoder ABC280: Ex. Substring Sort
10351 AtCoder ABC280: G. Do Use Hexagon Grid 2
10350 AtCoder ABC280: F. Pay or Receive
10349 AtCoder ABC280: E. Critical Hit
10348 AtCoder ABC280: D. Factorial and Multiple
10347 AtCoder ABC280: C. Extra Character
10346 AtCoder ABC280: B. Inverse Prefix Sum
10345 AtCoder ABC280: A. Pawn on a Grid
10344 AtCoder ABC279: Ex. Sum of Prod of Min
10343 AtCoder ABC279: G. At Most 2 Colors
10342 AtCoder ABC279: F. BOX
10341 AtCoder ABC279: E. Cheating Amidakuji
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