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)
14851	AtCoder WTF19-OPEN: C2. Triangular Lamps Hard
14850	AtCoder WTF19-OPEN: C1. Triangular Lamps Easy
14849	AtCoder WTF19-OPEN: B. Multiple of Nine
14848	AtCoder WTF19-OPEN: A. Magic
14847	AtCoder WN2017_1: A. Satellite data compression
14846	AtCoder UTPC2022: O. Move to Rest
14845	AtCoder UTPC2022: N. 01 String Game
14844	AtCoder UTPC2022: M. Minimize XOR by Redistribution
14843	AtCoder UTPC2022: L. Small RPS Tournament
14842	AtCoder UTPC2022: K. Grid Coloring
14841	AtCoder UTPC2022: J. Divide and Sort
14840	AtCoder UTPC2022: I. Which must be deleted?
14839	AtCoder UTPC2022: H. Digit Slot
14838	AtCoder UTPC2022: G. K flipping
14837	AtCoder UTPC2022: F. K inversions
14836	AtCoder UTPC2022: E. Parallel Swapping
14835	AtCoder UTPC2022: D. Balance
14834	AtCoder UTPC2022: C. Nim is Time-consuming
14833	AtCoder UTPC2022: B. Cross Laser Beam
14832	AtCoder UTPC2022: A. Shuffle and GCD
14831	AtCoder UTPC2021: N. Tree Swapping
14830	AtCoder UTPC2021: M. Open the Door
14829	AtCoder UTPC2021: L. Maze Game
14828	AtCoder UTPC2021: K. Divide Polynomials by #Subset Sums
14827	AtCoder UTPC2021: J. Do you like Interval Scheduling Problems?
14826	AtCoder UTPC2021: I. Card Decks
14825	AtCoder UTPC2021: H. Quantum Multiplication
14824	AtCoder UTPC2021: G. Matrix Compressor
14823	AtCoder UTPC2021: F. Red and Blue Medals
14822	AtCoder UTPC2021: E. Bounding Box
14821	AtCoder UTPC2021: D. Chain Graph Pair
14820	AtCoder UTPC2021: C. Product Matching
14819	AtCoder UTPC2021: B. Swap and Maximize
14818	AtCoder UTPC2021: A. Make UTPC
14817	AtCoder UTPC2020: M. Not Another Geometry Game!
14816	AtCoder UTPC2020: L. Euclidean Distance Product
14815	AtCoder UTPC2020: K. Special Chopsticks
14814	AtCoder UTPC2020: J. Merge and Decrement
14813	AtCoder UTPC2020: I. UTPC Kingdom
14812	AtCoder UTPC2020: H. Grid Eraser
14811	AtCoder UTPC2020: G. D. D. Construction
14810	AtCoder UTPC2020: F. Save Your MP
14809	AtCoder UTPC2020: E. Sort Segments
14808	AtCoder UTPC2020: D. Idol Group Costume
14807	AtCoder UTPC2020: C. Range Flip
14806	AtCoder UTPC2020: B. JANKEN Machine
14805	AtCoder UTPC2020: A. Row of Tents
14804	AtCoder UTPC2014: L. セミ時雨ハッシュ
14803	AtCoder UTPC2014: K. 乱数調整
14802	AtCoder UTPC2014: J. 看板の塗り替え

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

14851

AtCoder WTF19-OPEN: C2. Triangular Lamps Hard

14850

AtCoder WTF19-OPEN: C1. Triangular Lamps Easy

14849

AtCoder WTF19-OPEN: B. Multiple of Nine

14848

AtCoder WTF19-OPEN: A. Magic

14847

AtCoder WN2017_1: A. Satellite data compression

14846