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)
24001	Codeforces 1879D: Sum of XOR Functions
24000	Codeforces 1879C: Make it Alternating
23999	Codeforces 1879B: Chips on the Board
23998	Codeforces 1879A: Rigged!
23997	Codeforces 1878G: wxhtzdy ORO Tree
23996	Codeforces 1878F: Vasilije Loves Number Theory
23995	Codeforces 1878E: Iva & Pav
23994	Codeforces 1878D: Reverse Madness
23993	Codeforces 1878C: Vasilije in Cacak
23992	Codeforces 1878B: Aleksa and Stack
23991	Codeforces 1878A: How Much Does Daytona Cost?
23990	Codeforces 1875D: Jellyfish and Mex
23989	Codeforces 1875C: Jellyfish and Green Apple
23988	Codeforces 1875A: Jellyfish and Undertale
23987	Codeforces 1874G: Jellyfish and Inscryption
23986	Codeforces 1874F: Jellyfish and OEIS
23985	Codeforces 1874E: Jellyfish and Hack
23984	Codeforces 1874D: Jellyfish and Miku
23983	Codeforces 1874C: Jellyfish and EVA
23982	Codeforces 1874B: Jellyfish and Math
23981	Codeforces 1874A: Jellyfish and Game
23980	Codeforces 1873H: Mad City
23979	Codeforces 1873G: ABBC or BACB
23978	Codeforces 1873F: Money Trees
23977	Codeforces 1873E: Building an Aquarium
23976	Codeforces 1873D: 1D Eraser
23975	Codeforces 1873C: Target Practice
23974	Codeforces 1873B: Good Kid
23973	Codeforces 1873A: Short Sort
23972	DMOJ APIO '22 P3 - Permutation
23971	AtCoder ARC165: F. Make Adjacent
23970	AtCoder ARC165: E. Random Isolation
23969	AtCoder ARC165: D. Substring Comparison
23968	AtCoder ARC165: C. Social Distance on Graph
23967	AtCoder ARC165: B. Sliding Window Sort 2
23966	AtCoder ARC165: A. Sum equals LCM
23965	AtCoder ABC320: G. Slot Strategy 2 (Hard)
23964	AtCoder ABC320: F. Fuel Round Trip
23963	AtCoder ABC320: E. Somen Nagashi
23962	AtCoder ABC320: D. Relative Position
23961	AtCoder ABC320: C. Slot Strategy 2 (Easy)
23960	AtCoder ABC320: B. Longest Palindrome
23959	AtCoder ABC320: A. Leyland Number
23958	Codeforces 1870H: Standard Graph Problem
23957	Codeforces 1870G: MEXanization
23956	Codeforces 1870F: Lazy Numbers
23955	Codeforces 1870E: Another MEX Problem
23954	Codeforces 1870D: Prefix Purchase
23953	Codeforces 1870C: Colorful Table
23952	Codeforces 1870B: Friendly Arrays

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

24001

Codeforces 1879D: Sum of XOR Functions

24000

Codeforces 1879C: Make it Alternating

23999

Codeforces 1879B: Chips on the Board

23998

Codeforces 1879A: Rigged!

23997

Codeforces 1878G: wxhtzdy ORO Tree

23996