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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)
7455 Codeforces 1621A: Stable Arrangement of Rooks
7454 Codeforces 1620G: Subsequences Galore
7453 Codeforces 1620F: Bipartite Array
7452 Codeforces 1620E: Replace the Numbers
7451 Codeforces 1620D: Exact Change
7450 Codeforces 1620C: BA-String
7449 Codeforces 1620B: Triangles on a Rectangle
7448 Codeforces 1620A: Equal or Not Equal
7447 Codeforces 1619H: Permutation and Queries
7446 Codeforces 1619G: Unusual Minesweeper
7445 Codeforces 1619F: Let's Play the Hat?
7444 Codeforces 1619E: MEX and Increments
7443 Codeforces 1619D: New Year's Problem
7442 Codeforces 1619C: Wrong Addition
7441 Codeforces 1619B: Squares and Cubes
7440 Codeforces 1619A: Square String?
7439 Codeforces 1618G: Trader Problem
7438 Codeforces 1618F: Reverse
7437 Codeforces 1618E: Singers' Tour
7436 Codeforces 1618D: Array and Operations
7435 Codeforces 1618C: Paint the Array
7434 Codeforces 1618B: Missing Bigram
7433 Codeforces 1618A: Polycarp and Sums of Subsequences
7432 Codeforces 1617E: Christmas Chocolates
7431 Codeforces 1617D2: Too Many Impostors (hard version)
7430 Codeforces 1617D1: Too Many Impostors (easy version)
7429 Codeforces 1617C: Paprika and Permutation
7428 Codeforces 1617B: GCD Problem
7427 Codeforces 1617A: Forbidden Subsequence
7426 Codeforces 1616H: Keep XOR Low
7425 Codeforces 1616G: Just Add an Edge
7424 Codeforces 1616F: Tricolor Triangles
7423 Codeforces 1616E: Lexicographically Small Enough
7422 Codeforces 1616D: Keep the Average High
7421 Codeforces 1616C: Representative Edges
7420 Codeforces 1616B: Mirror in the String
7419 Codeforces 1616A: Integer Diversity
7418 Codeforces 1615H: Reindeer Games
7417 Codeforces 1615G: Maximum Adjacent Pairs
7416 Codeforces 1615F: LEGOndary Grandmaster
7415 Codeforces 1615E: Purple Crayon
7414 Codeforces 1615D: X(or)-mas Tree
7413 Codeforces 1615C: Menorah
7412 Codeforces 1615B: And It's Non-Zero
7411 Codeforces 1615A: Closing The Gap
7410 Codeforces 1614E: Divan and a Cottage
7409 Codeforces 1614D2: Divan and Kostomuksha (hard version)
7408 Codeforces 1614D1: Divan and Kostomuksha (easy version)
7407 Codeforces 1614C: Divan and bitwise operations
7406 Codeforces 1614B: Divan and a New Project
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