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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)
650 Codeforces 135C: Zero-One
649 Codeforces 135B: Rectangle and Square
648 Codeforces 135A: Replacement
647 Codeforces 134C: Swaps
646 Codeforces 134B: Pairs of Numbers
645 Codeforces 134A: Average Numbers
644 Codeforces 133B: Unary
643 Codeforces 133A: HQ9+
642 Codeforces 132E: Bits of merry old England
641 Codeforces 132D: Constants in the language of Shakespeare
640 Codeforces 132C: Logo Turtle
639 Codeforces 132B: Piet
638 Codeforces 132A: Turing Tape
637 Codeforces 131F: Present to Mom
636 Codeforces 131E: Yet Another Task with Queens
635 Codeforces 131D: Subway
634 Codeforces 131C: The World is a Theatre
633 Codeforces 131B: Opposites Attract
632 Codeforces 131A: cAPS lOCK
631 Codeforces 130J: Date calculation
630 Codeforces 130I: Array sorting
629 Codeforces 130H: Balanced brackets
628 Codeforces 130G: CAPS LOCK ON
627 Codeforces 130F: Prime factorization
626 Codeforces 130E: Tribonacci numbers
625 Codeforces 130D: Exponentiation
624 Codeforces 130C: Decimal sum
623 Codeforces 130B: Gnikool Ssalg
622 Codeforces 130A: Hexagonal numbers
621 Codeforces 129B: Students and Shoelaces
620 Codeforces 129A: Cookies
619 Codeforces 128E: Birthday
618 Codeforces 128D: Numbers
617 Codeforces 128C: Games with Rectangle
616 Codeforces 128B: String
615 Codeforces 128A: Statues
614 Codeforces 127B: Canvas Frames
613 Codeforces 127A: Wasted Time
612 Codeforces 126E: Pills
611 Codeforces 126D: Fibonacci Sums
610 Codeforces 126C: E-reader Display
609 Codeforces 126B: Password
608 Codeforces 126A: Hot Bath
607 Codeforces 125E: MST Company
606 Codeforces 125D: Two progressions
605 Codeforces 125C: Hobbits' Party
604 Codeforces 125B: Simple XML
603 Codeforces 125A: Measuring Lengths in Baden
602 Codeforces 124B: Permutations
601 Codeforces 124A: The number of positions
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