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)
17701	DMOJ Fibonacci Sequence (Harder)
17700	DMOJ Fibonacci Sequence
17699	DMOJ Facebook Hacker Cup '19 Final Round P6 - Temporal Revision
17698	DMOJ Facebook Hacker Cup '19 Final Round P1 - Strings as a Service
17697	DMOJ Facebook Hacker Cup '17 Qualifying Round P3 - Fighting the Zombie
17696	DMOJ Facebook Hacker Cup '17 Qualifying Round P2 - Lazy Loading
17695	DMOJ Facebook Hacker Cup '17 Qualifying Round P1 - Progress Pie
17694	DMOJ Facebook Hacker Cup '15 Round 3 P4 - Fox Rocks
17693	DMOJ Facebook Hacker Cup '15 Round 3 P3 - Gentrification
17692	DMOJ Facebook Hacker Cup '15 Round 3 P2 - Lunch Scheduling
17691	DMOJ Facebook Hacker Cup '15 Round 3 P1 - Boomerang
17690	DMOJ Facebook Hacker Cup '15 Round 2 P4 - Fox Socks
17689	DMOJ Facebook Hacker Cup '15 Round 2 P3 - Autocomplete Strikes Back
17688	DMOJ Facebook Hacker Cup '15 Round 2 P2 - All Critical
17687	DMOJ Facebook Hacker Cup '15 Round 2 P1 - Lazy Sort
17686	DMOJ Facebook Hacker Cup '15 Round 1 P4 - Corporate Gifting
17685	DMOJ Facebook Hacker Cup '15 Round 1 P3 - Winning at Sports
17684	DMOJ Facebook Hacker Cup '15 Round 1 P2 - Autocomplete
17683	DMOJ Facebook Hacker Cup '15 Round 1 P1 - Homework
17682	DMOJ Facebook Hacker Cup '14 Final Round P4 - Tours
17681	DMOJ Facebook Hacker Cup '14 Final Round P3 - Fortunate Wheels
17680	DMOJ Favorite Numbers
17679	DMOJ The Codefather
17678	DMOJ Fast LCA (Hard)
17677	DMOJ Fast LCA
17676	DMOJ Fast Bit Counting
17675	DMOJ Falling Snowflakes
17674	DMOJ Fair Competition
17673	DMOJ Factors
17672	DMOJ Factorial Calculator
17671	DMOJ Fast Factorial Calculator 3
17670	DMOJ Fast Factorial Calculator 2
17669	DMOJ Fast Factorial Calculator
17668	DMOJ Expected Value
17667	DMOJ Executable Format
17666	DMOJ Exam Prep
17665	DMOJ Evan's Cube
17664	DMOJ ETSR '23 Onsite Round 2 Problem 3 - Trees
17663	DMOJ ETSR '23 Onsite Round 2 Problem 2 - Exponents
17662	DMOJ ETSR '23 Onsite Round 2 Problem 1 - Bracket
17661	DMOJ ETSR '23 Onsite Round 1 Problem 3 - Travel
17660	DMOJ ETSR '23 Onsite Round 1 Problem 2 - Origami
17659	DMOJ ETSR '23 Onsite Round 1 Problem 1 - Arithmetic
17658	DMOJ ETSR '23 Online Round 2 Problem 4 - Queue
17657	DMOJ ETSR '23 Online Round 2 Problem 3 - Stone Game
17656	DMOJ ETSR '23 Online Round 2 Problem 2 - Equation
17655	DMOJ ETSR '23 Online Round 2 Problem 1 - Pencil
17654	DMOJ Equivalent Addresses
17653	DMOJ Encode
17652	DMOJ Emoji Search

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

17701

DMOJ Fibonacci Sequence (Harder)

17700

DMOJ Fibonacci Sequence

17699

DMOJ Facebook Hacker Cup '19 Final Round P6 - Temporal Revision

17698

DMOJ Facebook Hacker Cup '19 Final Round P1 - Strings as a Service

17697

DMOJ Facebook Hacker Cup '17 Qualifying Round P3 - Fighting the Zombie

17696