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)
23951	Codeforces 1870A: MEXanized Array
23950	AtCoder AHC023: A-Final. Crops on Grid (System Test)
23949	AtCoder AHC023: A. Crops on Grid
23948	Codeforces 1869B: 2D Traveling
23947	Codeforces 1869A: Make It Zero
23946	Codeforces 1868F: LIS?
23945	Codeforces 1868E: Min-Sum-Max
23944	Codeforces 1868D: Flower-like Pseudotree
23943	Codeforces 1868C: Travel Plan
23942	Codeforces 1868B2: Candy Party (Hard Version)
23941	Codeforces 1868B1: Candy Party (Easy Version)
23940	Codeforces 1868A: Fill in the Matrix
23939	Codeforces 1867F: Most Different Tree
23938	Codeforces 1867E2: Salyg1n and Array (hard version)
23937	Codeforces 1867E1: Salyg1n and Array (simple version)
23936	Codeforces 1867D: Cyclic Operations
23935	Codeforces 1867C: Salyg1n and the MEX Game
23934	Codeforces 1867B: XOR Palindromes
23933	Codeforces 1867A: green_gold_dog, array and permutation
23932	AtCoder WTF22-DAY2: E. Adjacent Xor Game
23931	AtCoder WTF22-DAY2: D. Cat Jumps
23930	AtCoder WTF22-DAY2: C. Jewel Pairs
23929	AtCoder WTF22-DAY2: B. The Greatest Two
23928	AtCoder WTF22-DAY2: A. Hat Puzzle
23927	AtCoder WTF22-DAY1-OPEN: E. Sort A[i]-i
23926	AtCoder WTF22-DAY1-OPEN: D. Welcome to Tokyo!
23925	AtCoder WTF22-DAY1-OPEN: C. Shrink the Tree
23924	AtCoder WTF22-DAY1-OPEN: B. Non-Overlapping Swaps
23923	AtCoder WTF22-DAY1-OPEN: A. Save the Monsters
23922	AtCoder ABC319: G. Counting Shortest Paths
23921	AtCoder ABC319: F. Fighter Takahashi
23920	AtCoder ABC319: E. Bus Stops
23919	AtCoder ABC319: D. Minimum Width
23918	AtCoder ABC319: C. False Hope
23917	AtCoder ABC319: B. Measure
23916	AtCoder ABC319: A. Legendary Players
23915	Codeforces 1872G: Replace With Product
23914	Codeforces 1872F: Selling a Menagerie
23913	Codeforces 1872E: Data Structures Fan
23912	Codeforces 1872D: Plus Minus Permutation
23911	Codeforces 1872C: Non-coprime Split
23910	Codeforces 1872B: The Corridor or There and Back Again
23909	Codeforces 1872A: Two Vessels
23908	DMOJ IOI '23 P6 - Robot Contest
23907	DMOJ IOI '23 P5 - Overtaking
23906	DMOJ IOI '23 P4 - Beech Tree
23905	Codeforces 1866M: Mighty Rock Tower
23904	Codeforces 1866L: Lihmuf Balling
23903	Codeforces 1866K: Keen Tree Calculation
23902	Codeforces 1866J: Jackets and Packets

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

23951

Codeforces 1870A: MEXanized Array

23950

AtCoder AHC023: A-Final. Crops on Grid (System Test)

23949

AtCoder AHC023: A. Crops on Grid

23948

Codeforces 1869B: 2D Traveling

23947

Codeforces 1869A: Make It Zero

23946