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.

Need help searching? Click for format/examples of problems

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)
12001	AtCoder CODE-FESTIVAL-2017-QUALC: D. Yet Another Palindrome Partitioning
12000	AtCoder CODE-FESTIVAL-2017-QUALC: C. Inserting 'x'
11999	AtCoder CODE-FESTIVAL-2017-QUALC: B. Similar Arrays
11998	AtCoder CODE-FESTIVAL-2017-QUALC: A. Can you get AC?
11997	AtCoder CODE-FESTIVAL-2017-QUALB: F. Largest Smallest Cyclic Shift
11996	AtCoder CODE-FESTIVAL-2017-QUALB: E. Popping Balls
11995	AtCoder CODE-FESTIVAL-2017-QUALB: D. 101 to 010
11994	AtCoder CODE-FESTIVAL-2017-QUALB: C. 3 Steps
11993	AtCoder CODE-FESTIVAL-2017-QUALB: B. Problem Set
11992	AtCoder CODE-FESTIVAL-2017-QUALB: A. XXFESTIVAL
11991	AtCoder CODE-FESTIVAL-2017-QUALA: F. Squeezing Slimes
11990	AtCoder CODE-FESTIVAL-2017-QUALA: E. Modern Painting
11989	AtCoder CODE-FESTIVAL-2017-QUALA: D. Four Coloring
11988	AtCoder CODE-FESTIVAL-2017-QUALA: C. Palindromic Matrix
11987	AtCoder CODE-FESTIVAL-2017-QUALA: B. fLIP
11986	AtCoder CODE-FESTIVAL-2017-QUALA: A. Snuke's favorite YAKINIKU
11985	AtCoder CODE-FESTIVAL-2015-OKINAWA-OPEN: J. Jungle
11984	AtCoder CODE-FESTIVAL-2015-OKINAWA-OPEN: I. Implementation Addict
11983	AtCoder CODE-FESTIVAL-2015-OKINAWA-OPEN: H. Happy 2015
11982	AtCoder CODE-FESTIVAL-2015-OKINAWA-OPEN: G. Gorgeous Vases
11981	AtCoder CODE-FESTIVAL-2015-OKINAWA-OPEN: F. Falconry
11980	AtCoder CODE-FESTIVAL-2015-OKINAWA-OPEN: E. Enormous XOR Rectangle
11979	AtCoder CODE-FESTIVAL-2015-OKINAWA-OPEN: D. Dictionary for Shiritori Game
11978	AtCoder CODE-FESTIVAL-2015-OKINAWA-OPEN: C. Cat versus Wolf
11977	AtCoder CODE-FESTIVAL-2015-OKINAWA-OPEN: B. Beware of the Sogginess!
11976	AtCoder CODE-FESTIVAL-2015-OKINAWA-OPEN: A. Automatic Map Generator
11975	AtCoder CHOKUDAI_S002: L. 長方形 β
11974	AtCoder CHOKUDAI_S002: K. 種類数 β
11973	AtCoder CHOKUDAI_S002: J. GCD β
11972	AtCoder CHOKUDAI_S002: I. カツサンドくん β
11971	AtCoder CHOKUDAI_S002: H. あまり β
11970	AtCoder CHOKUDAI_S002: G. GCD α
11969	AtCoder CHOKUDAI_S002: F. 種類数 α
11968	AtCoder CHOKUDAI_S002: E. カツサンドくん α
11967	AtCoder CHOKUDAI_S002: D. 和の最大値 β
11966	AtCoder CHOKUDAI_S002: C. 和の最大値 α
11965	AtCoder CHOKUDAI_S002: B. あまり α
11964	AtCoder CHOKUDAI_S002: A. 長方形 α
11963	AtCoder CHOKUDAI_S001: L. N回スワップ
11962	AtCoder CHOKUDAI_S001: K. 辞書順で何番目？
11961	AtCoder CHOKUDAI_S001: J. 転倒数
11960	AtCoder CHOKUDAI_S001: I. 和がNの区間
11959	AtCoder CHOKUDAI_S001: H. LIS
11958	AtCoder CHOKUDAI_S001: G. あまり
11957	AtCoder CHOKUDAI_S001: F. 見える数
11956	AtCoder CHOKUDAI_S001: E. 1は何番目？
11955	AtCoder CHOKUDAI_S001: D. ソート
11954	AtCoder CHOKUDAI_S001: C. カンマ区切り
11953	AtCoder CHOKUDAI_S001: B. 和
11952	AtCoder CHOKUDAI_S001: A. 最大値

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

12001

AtCoder CODE-FESTIVAL-2017-QUALC: D. Yet Another Palindrome Partitioning

12000

AtCoder CODE-FESTIVAL-2017-QUALC: C. Inserting 'x'

11999

AtCoder CODE-FESTIVAL-2017-QUALC: B. Similar Arrays

11998

AtCoder CODE-FESTIVAL-2017-QUALC: A. Can you get AC?

11997

AtCoder CODE-FESTIVAL-2017-QUALB: F. Largest Smallest Cyclic Shift

11996