Starlight: List of Problems

Over 20,000 problems available. AMC 8/10/12 and AIME problems from 2010-2023; USAJMO/USAMO problems from 2002-2023 available. USACO problems from 2014 to 2023 (all divisions). Codeforces, AtCoder, DMOJ problems are added daily around 04:00 AM UTC, which may cause disruptions.

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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)
14001	AtCoder PAST202206-OPEN: E. Strange Sequence
14000	AtCoder PAST202206-OPEN: D. Similar Strings
13999	AtCoder PAST202206-OPEN: C. Order
13998	AtCoder PAST202206-OPEN: B. Two Letters
13997	AtCoder PAST202206-OPEN: A. The Tortoise and the Hare
13996	AtCoder PAST202203-OPEN: O. 3-Permutation
13995	AtCoder PAST202203-OPEN: N. 40B of calculations
13994	AtCoder PAST202203-OPEN: M. Ranking
13993	AtCoder PAST202203-OPEN: L. N mod M
13992	AtCoder PAST202203-OPEN: K. Planning
13991	AtCoder PAST202203-OPEN: J. Expected Range
13990	AtCoder PAST202203-OPEN: I. Symmetric Transformation
13989	AtCoder PAST202203-OPEN: H. Connected Components
13988	AtCoder PAST202203-OPEN: G. Equations
13987	AtCoder PAST202203-OPEN: F. Coloring map
13986	AtCoder PAST202203-OPEN: E. Only 2 kinds
13985	AtCoder PAST202203-OPEN: D. High Score
13984	AtCoder PAST202203-OPEN: C. Go Further
13983	AtCoder PAST202203-OPEN: B. Flowers
13982	AtCoder PAST202203-OPEN: A. Three cards
13981	AtCoder PAST202112-OPEN: O. Pair Score
13980	AtCoder PAST202112-OPEN: N. Intersection
13979	AtCoder PAST202112-OPEN: M. Deadnames
13978	AtCoder PAST202112-OPEN: L. Honest students
13977	AtCoder PAST202112-OPEN: K. Gas Station
13976	AtCoder PAST202112-OPEN: J. Rotate and Reverse
13975	AtCoder PAST202112-OPEN: I. Direct Elevator
13974	AtCoder PAST202112-OPEN: H. Longest Non-common Subsequence
13973	AtCoder PAST202112-OPEN: G. Connectivity
13972	AtCoder PAST202112-OPEN: F. Like As Shogi
13971	AtCoder PAST202112-OPEN: E. Keyboard
13970	AtCoder PAST202112-OPEN: D. Examination
13969	AtCoder PAST202112-OPEN: C. Fastest Answer
13968	AtCoder PAST202112-OPEN: B. Perforated Coin
13967	AtCoder PAST202112-OPEN: A. Attractions
13966	AtCoder PAST202109-OPEN: O. Red Blue Tournament
13965	AtCoder PAST202109-OPEN: N. Zigzag Sequences
13964	AtCoder PAST202109-OPEN: M. Balance
13963	AtCoder PAST202109-OPEN: L. K-th Abs
13962	AtCoder PAST202109-OPEN: K. Happy Wedding!
13961	AtCoder PAST202109-OPEN: J. Reverse Array
13960	AtCoder PAST202109-OPEN: I. /2 and *3
13959	AtCoder PAST202109-OPEN: H. Shortest Path
13958	AtCoder PAST202109-OPEN: G. K-th element
13957	AtCoder PAST202109-OPEN: F. Incomplete Permutation
13956	AtCoder PAST202109-OPEN: E. Colorful T-Shirts
13955	AtCoder PAST202109-OPEN: D. Divisor
13954	AtCoder PAST202109-OPEN: C. Number of Apperance
13953	AtCoder PAST202109-OPEN: B. intersection
13952	AtCoder PAST202109-OPEN: A. Bubbler

Problem Name (click to add insights/hints, view summary of insights/hints and similar problems)

14001

AtCoder PAST202206-OPEN: E. Strange Sequence

14000

AtCoder PAST202206-OPEN: D. Similar Strings

13999

AtCoder PAST202206-OPEN: C. Order

13998

AtCoder PAST202206-OPEN: B. Two Letters

13997

AtCoder PAST202206-OPEN: A. The Tortoise and the Hare

13996