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)
10651	AtCoder AGC003: C. BBuBBBlesort!
10650	AtCoder AGC003: B. Simplified mahjong
10649	AtCoder AGC003: A. Wanna go back home
10648	AtCoder AGC002: F. Leftmost Ball
10647	AtCoder AGC002: E. Candy Piles
10646	AtCoder AGC002: D. Stamp Rally
10645	AtCoder AGC002: C. Knot Puzzle
10644	AtCoder AGC002: B. Box and Ball
10643	AtCoder AGC002: A. Range Product
10642	AtCoder AGC001: F. Wide Swap
10641	AtCoder AGC001: E. BBQ Hard
10640	AtCoder AGC001: D. Arrays and Palindrome
10639	AtCoder AGC001: C. Shorten Diameter
10638	AtCoder AGC001: B. Mysterious Light
10637	AtCoder AGC001: A. BBQ Easy
10636	AtCoder ACL1: F. Center Rearranging
10635	AtCoder ACL1: E. Shuffle Window
10634	AtCoder ACL1: D. Keep Distances
10633	AtCoder ACL1: C. Moving Pieces
10632	AtCoder ACL1: B. Sum is Multiple
10631	AtCoder ACL1: A. Reachable Towns
10630	AtCoder ABL: F. Heights and Pairs
10629	AtCoder ABL: E. Replace Digits
10628	AtCoder ABL: D. Flat Subsequence
10627	AtCoder ABL: C. Connect Cities
10626	AtCoder ABL: B. Integer Preference
10625	AtCoder ABL: A. Repeat ACL
10624	AtCoder ABC314: Ex. Disk and Segments
10623	AtCoder ABC314: G. Amulets
10622	AtCoder ABC314: F. A Certain Game
10621	AtCoder ABC314: E. Roulettes
10620	AtCoder ABC314: D. LOWER
10619	AtCoder ABC314: C. Rotate Colored Subsequence
10618	AtCoder ABC314: B. Roulette
10617	AtCoder ABC314: A. 3.14
10616	AtCoder ABC313: Ex. Group Photo
10615	AtCoder ABC313: G. Redistribution of Piles
10614	AtCoder ABC313: F. Flip Machines
10613	AtCoder ABC313: E. Duplicate
10612	AtCoder ABC313: D. Odd or Even
10611	AtCoder ABC313: C. Approximate Equalization 2
10610	AtCoder ABC313: B. Who is Saikyo?
10609	AtCoder ABC313: A. To Be Saikyo
10608	AtCoder ABC312: Ex. snukesnuke
10607	AtCoder ABC312: G. Avoid Straight Line
10606	AtCoder ABC312: F. Cans and Openers
10605	AtCoder ABC312: E. Tangency of Cuboids
10604	AtCoder ABC312: D. Count Bracket Sequences
10603	AtCoder ABC312: C. Invisible Hand
10602	AtCoder ABC312: B. TaK Code

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

10651

AtCoder AGC003: C. BBuBBBlesort!

10650

AtCoder AGC003: B. Simplified mahjong

10649

AtCoder AGC003: A. Wanna go back home

10648

AtCoder AGC002: F. Leftmost Ball

10647

AtCoder AGC002: E. Candy Piles

10646