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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)
25147 Codeforces 1970A2: Balanced Unshuffle (Medium)
25146 Codeforces 1970A1: Balanced Shuffle (Easy)
25145 Codeforces 1969F: Card Pairing
25144 Codeforces 1969E: Unique Array
25143 Codeforces 1969D: Shop Game
25142 Codeforces 1969C: Minimizing the Sum
25141 Codeforces 1969B: Shifts and Sorting
25140 Codeforces 1969A: Two Friends
25139 Codeforces 1968G2: Division + LCP (hard version)
25138 Codeforces 1968G1: Division + LCP (easy version)
25137 Codeforces 1968F: Equal XOR Segments
25136 Codeforces 1968E: Cells Arrangement
25135 Codeforces 1968D: Permutation Game
25134 Codeforces 1968C: Assembly via Remainders
25133 Codeforces 1968B: Prefiquence
25132 Codeforces 1968A: Maximize?
25131 Codeforces 1967F: Next and Prev
25130 Codeforces 1967E2: Again Counting Arrays (Hard Version)
25129 Codeforces 1967E1: Again Counting Arrays (Easy Version)
25128 Codeforces 1967D: Long Way to be Non-decreasing
25127 Codeforces 1967C: Fenwick Tree
25126 Codeforces 1967B2: Reverse Card (Hard Version)
25125 Codeforces 1967B1: Reverse Card (Easy Version)
25124 Codeforces 1967A: Permutation Counting
25123 Codeforces 1966B: Rectangle Filling
25122 Codeforces 1966A: Card Exchange
25121 Codeforces 1965F: Conference
25120 Codeforces 1965E: Connected Cubes
25119 Codeforces 1965D: Missing Subarray Sum
25118 Codeforces 1965C: Folding Strip
25117 Codeforces 1965B: Missing Subsequence Sum
25116 Codeforces 1965A: Everything Nim
25115 Codeforces 1958J: Necromancer
25114 Codeforces 1958I: Equal Trees
25113 Codeforces 1958H: Composite Spells
25112 Codeforces 1958G: Observation Towers
25111 Codeforces 1958F: Narrow Paths
25110 Codeforces 1958E: Yet Another Permutation Constructive
25109 Codeforces 1958D: Staircase
25108 Codeforces 1958C: Firewood
25107 Codeforces 1958B: Clock in the Pool
25106 Codeforces 1958A: 1-3-5
25105 Codeforces 1957F2: Frequency Mismatch (Hard Version)
25104 Codeforces 1957F1: Frequency Mismatch (Easy Version)
25103 Codeforces 1957E: Carousel of Combinations
25102 Codeforces 1957D: A BIT of an Inequality
25101 Codeforces 1957C: How Does the Rook Move?
25100 Codeforces 1957B: A BIT of a Construction
25099 Codeforces 1957A: Stickogon
25098 Codeforces 1956F: Nene and the Passing Game
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