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)
18683 DMOJ NOI '13 P5 - Calligrapher
18682 DMOJ NOI '13 P4 - Matrix Game
18681 DMOJ NOI '13 P3 - Little Q's Training
18680 DMOJ NOI '13 P2 - Tree Count
18679 DMOJ NOI '13 P1 - Inner Product
18678 DMOJ NOI '12 P6 - Triple Town
18677 DMOJ NOI '12 P5 - Food Festival
18676 DMOJ NOI '12 P4 - Lost in the Park
18675 DMOJ NOI '12 P3 - Magic Chessboard
18674 DMOJ NOI '12 P2 - Highway Cycling
18673 DMOJ NOI '12 P1 - Random Number Generator
18672 DMOJ NOI '11 P6 - Bunny and Eggy's Game
18671 DMOJ NOI '11 P5 - NOI Carnival
18670 DMOJ NOI '11 P4 - Road Construction
18669 DMOJ NOI '11 P3 - Ali's Typewriter
18668 DMOJ NOI '11 P2 - Intelligent Car Racing
18667 DMOJ NOI '11 P1 - Rabbit Farming
18666 DMOJ NOI '10 P6 - Happily Growing
18665 DMOJ NOI '10 P5 - Route Planning
18664 DMOJ NOI '10 P4 - Flight Control
18663 DMOJ NOI '10 P3 - Altitude
18662 DMOJ NOI '10 P2 - Super Piano
18661 DMOJ NOI '10 P1 - Energy Harvesting
18660 DMOJ NOI '09 P6 - Tracing
18659 DMOJ NOI '09 P5 - Pipe Marbles
18658 DMOJ NOI '09 P4 - Plants vs. Zombies
18657 DMOJ NOI '09 P3 - Modified Treap
18656 DMOJ NOI '09 P2 - Little G the Poet
18655 DMOJ NOI '09 P1 - Transformed Sequence
18654 DMOJ NOI '08 P6 - Tournament Matching
18653 DMOJ NOI '08 P5 - Candy Rain
18652 DMOJ NOI '08 P4 - Olympic Logistics
18651 DMOJ NOI '08 P3 - Hiring Employees
18650 DMOJ NOI '08 P2 - Course Design
18649 DMOJ NOI '08 P1 - Masquerade Party
18648 DMOJ NOI '07 P6 - Thief Catching
18647 DMOJ NOI '07 P5 - Counting Spanning Trees
18646 DMOJ NOI '07 P4 - Necklace Factory
18645 DMOJ NOI '07 P3 - Surrounding Battalions
18644 DMOJ NOI '07 P2 - Cash Exchange
18643 DMOJ NOI '07 P1 - Social Network
18642 DMOJ NOI '06 P6 - The Magical Bag
18641 DMOJ NOI '06 P5 - The Clever Tour Guide
18640 DMOJ NOI '06 P4 - Maximum Profit
18639 DMOJ NOI '06 P3 - Millennium Worm
18638 DMOJ NOI '06 P1 - Network Charges
18637 DMOJ NOI '05 P6 - Lemon Tree Under the Moon
18636 DMOJ NOI '05 P5 - Little H's Party
18635 DMOJ NOI '05 P4 - CongCong and KoKo
18634 DMOJ NOI '05 P3 - Wisdom Beads Game
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