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)
8701	Codeforces 1835E: Old Mobile
8700	Codeforces 1835D: Doctor's Brown Hypothesis
8699	Codeforces 1835C: Twin Clusters
8698	Codeforces 1835B: Lottery
8697	Codeforces 1835A: k-th equality
8696	Codeforces 1834F: Typewriter
8695	Codeforces 1834E: MEX of LCM
8694	Codeforces 1834D: Survey in Class
8693	Codeforces 1834C: Game with Reversing
8692	Codeforces 1834B: Maximum Strength
8691	Codeforces 1834A: Unit Array
8690	Codeforces 1833G: Ksyusha and Chinchilla
8689	Codeforces 1833F: Ira and Flamenco
8688	Codeforces 1833E: Round Dance
8687	Codeforces 1833D: Flipper
8686	Codeforces 1833C: Vlad Building Beautiful Array
8685	Codeforces 1833B: Restore the Weather
8684	Codeforces 1833A: Musical Puzzle
8683	Codeforces 1832F: Zombies
8682	Codeforces 1832E: Combinatorics Problem
8681	Codeforces 1832D2: Red-Blue Operations (Hard Version)
8680	Codeforces 1832D1: Red-Blue Operations (Easy Version)
8679	Codeforces 1832C: Contrast Value
8678	Codeforces 1832B: Maximum Sum
8677	Codeforces 1832A: New Palindrome
8676	Codeforces 1831B: Array merging
8675	Codeforces 1831A: Twin Permutations
8674	Codeforces 1830F: The Third Grace
8673	Codeforces 1830E: Bully Sort
8672	Codeforces 1830D: Mex Tree
8671	Codeforces 1830C: Hyperregular Bracket Strings
8670	Codeforces 1830B: The BOSS Can Count Pairs
8669	Codeforces 1830A: Copil Copac Draws Trees
8668	Codeforces 1829H: Don't Blame Me
8667	Codeforces 1829G: Hits Different
8666	Codeforces 1829F: Forever Winter
8665	Codeforces 1829E: The Lakes
8664	Codeforces 1829D: Gold Rush
8663	Codeforces 1829C: Mr. Perfectly Fine
8662	Codeforces 1829B: Blank Space
8661	Codeforces 1829A: Love Story
8660	Codeforces 1828B: Permutation Swap
8659	Codeforces 1828A: Divisible Array
8658	Codeforces 1827F: Copium Permutation
8657	Codeforces 1827E: Bus Routes
8656	Codeforces 1827D: Two Centroids
8655	Codeforces 1827C: Palindrome Partition
8654	Codeforces 1827B2: Range Sorting (Hard Version)
8653	Codeforces 1827B1: Range Sorting (Easy Version)
8652	Codeforces 1827A: Counting Orders

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

8701

Codeforces 1835E: Old Mobile

8700

Codeforces 1835D: Doctor's Brown Hypothesis

8699

Codeforces 1835C: Twin Clusters

8698

Codeforces 1835B: Lottery

8697

Codeforces 1835A: k-th equality

8696