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)
6801	Codeforces 1499B: Binary Removals
6800	Codeforces 1499A: Domino on Windowsill
6799	Codeforces 1498F: Christmas Game
6798	Codeforces 1498E: Two Houses
6797	Codeforces 1498D: Bananas in a Microwave
6796	Codeforces 1498C: Planar Reflections
6795	Codeforces 1498B: Box Fitting
6794	Codeforces 1498A: GCD Sum
6793	Codeforces 1497E2: Square-free division (hard version)
6792	Codeforces 1497E1: Square-Free Division (easy version)
6791	Codeforces 1497D: Genius
6790	Codeforces 1497C2: k-LCM (hard version)
6789	Codeforces 1497C1: k-LCM (easy version)
6788	Codeforces 1497B: M-arrays
6787	Codeforces 1497A: Meximization
6786	Codeforces 1496B: Max and Mex
6785	Codeforces 1496A: Split it!
6784	Codeforces 1495F: Squares
6783	Codeforces 1495E: Qingshan and Daniel
6782	Codeforces 1495D: BFS Trees
6781	Codeforces 1495C: Garden of the Sun
6780	Codeforces 1495B: Let's Go Hiking
6779	Codeforces 1495A: Diamond Miner
6778	Codeforces 1494F: Delete The Edges
6777	Codeforces 1494E: A-Z Graph
6776	Codeforces 1494D: Dogeforces
6775	Codeforces 1494C: 1D Sokoban
6774	Codeforces 1494B: Berland Crossword
6773	Codeforces 1494A: ABC String
6772	Codeforces 1493F: Enchanted Matrix
6771	Codeforces 1493E: Enormous XOR
6770	Codeforces 1493D: GCD of an Array
6769	Codeforces 1493C: K-beautiful Strings
6768	Codeforces 1493B: Planet Lapituletti
6767	Codeforces 1493A: Anti-knapsack
6766	Codeforces 1492E: Almost Fault-Tolerant Database
6765	Codeforces 1492D: Genius's Gambit
6764	Codeforces 1492C: Maximum width
6763	Codeforces 1492B: Card Deck
6762	Codeforces 1492A: Three swimmers
6761	Codeforces 1491I: Ruler Of The Zoo
6760	Codeforces 1491H: Yuezheng Ling and Dynamic Tree
6759	Codeforces 1491G: Switch and Flip
6758	Codeforces 1491F: Magnets
6757	Codeforces 1491E: Fib-tree
6756	Codeforces 1491D: Zookeeper and The Infinite Zoo
6755	Codeforces 1491C: Pekora and Trampoline
6754	Codeforces 1491B: Minimal Cost
6753	Codeforces 1491A: K-th Largest Value
6752	Codeforces 1490G: Old Floppy Drive

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

6801

Codeforces 1499B: Binary Removals

6800

Codeforces 1499A: Domino on Windowsill

6799

Codeforces 1498F: Christmas Game

6798

Codeforces 1498E: Two Houses

6797

Codeforces 1498D: Bananas in a Microwave

6796