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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)
4300 Codeforces 1002E2: Another array reconstruction algorithm
4299 Codeforces 1002E1: Bernstein-Vazirani algorithm
4298 Codeforces 1002D3: Oracle for majority function
4297 Codeforces 1002D2: Oracle for f(x) = b * x + (1 - b) * (1 - x) mod 2
4296 Codeforces 1002D1: Oracle for f(x) = b * x mod 2
4295 Codeforces 1002C2: Distinguish zero state and plus state without errors
4294 Codeforces 1002C1: Distinguish zero state and plus state with minimum error
4293 Codeforces 1002B4: Distinguish four 2-qubit states - 2
4292 Codeforces 1002B3: Distinguish four 2-qubit states
4291 Codeforces 1002B2: Distinguish GHZ state and W state
4290 Codeforces 1002B1: Distinguish zero state and W state
4289 Codeforces 1002A4: Generate W state
4288 Codeforces 1002A3: Generate superposition of two basis states
4287 Codeforces 1002A2: Generate superposition of zero state and a basis state
4286 Codeforces 1002A1: Generate superposition of all basis states
4285 Codeforces 1001I: Deutsch-Jozsa algorithm
4284 Codeforces 1001H: Oracle for f(x) = parity of the number of 1s in x
4283 Codeforces 1001G: Oracle for f(x) = k-th element of x
4282 Codeforces 1001F: Distinguish multi-qubit basis states
4281 Codeforces 1001E: Distinguish Bell states
4280 Codeforces 1001D: Distinguish plus state and minus state
4279 Codeforces 1001C: Generate GHZ state
4278 Codeforces 1001B: Generate Bell state
4277 Codeforces 1001A: Generate plus state or minus state
4276 Codeforces 1000G: Two-Paths
4275 Codeforces 1000F: One Occurrence
4274 Codeforces 1000E: We Need More Bosses
4273 Codeforces 1000D: Yet Another Problem On a Subsequence
4272 Codeforces 1000C: Covered Points Count
4271 Codeforces 1000B: Light It Up
4270 Codeforces 1000A: Codehorses T-shirts
4269 Codeforces 999F: Cards and Joy
4268 Codeforces 999E: Reachability from the Capital
4267 Codeforces 999D: Equalize the Remainders
4266 Codeforces 999C: Alphabetic Removals
4265 Codeforces 999B: Reversing Encryption
4264 Codeforces 999A: Mishka and Contest
4263 Codeforces 998B: Cutting
4262 Codeforces 998A: Balloons
4261 Codeforces 997E: Good Subsegments
4260 Codeforces 997D: Cycles in product
4259 Codeforces 997C: Sky Full of Stars
4258 Codeforces 997B: Roman Digits
4257 Codeforces 997A: Convert to Ones
4256 Codeforces 996B: World Cup
4255 Codeforces 996A: Hit the Lottery
4254 Codeforces 995F: Cowmpany Cowmpensation
4253 Codeforces 995E: Number Clicker
4252 Codeforces 995D: Game
4251 Codeforces 995C: Leaving the Bar
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