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)
11951	AtCoder CHOKUDAI001: A. 高橋君の山崩しゲーム
11950	AtCoder CHOKUDAI005: A. カラフルパネル
11949	AtCoder CHOKUDAI004: A. Just Write Numbers!
11948	AtCoder CHOKUDAI003: A. ○×ブロック
11947	AtCoder CHOKUDAI002: A. 約数をたくさんつくろう！
11946	AtCoder CODE-FESTIVAL-2015-RELAY: J. 石山ゲーム
11945	AtCoder CODE-FESTIVAL-2015-RELAY: I. Platoon Match
11944	AtCoder CODE-FESTIVAL-2015-RELAY: H. 塗りつぶし
11943	AtCoder CODE-FESTIVAL-2015-RELAY: G. 主菜と副菜
11942	AtCoder CODE-FESTIVAL-2015-RELAY: F. グラフの個数
11941	AtCoder CODE-FESTIVAL-2015-RELAY: E. 反転時計
11940	AtCoder CODE-FESTIVAL-2015-RELAY: D. ピザ
11939	AtCoder CODE-FESTIVAL-2015-RELAY: C. 円周率
11938	AtCoder CODE-FESTIVAL-2015-RELAY: B. 全完
11937	AtCoder CODE-FESTIVAL-2015-RELAY: A. チーム分け
11936	AtCoder CODE-FESTIVAL-2015-MORNING-HARD: D. ありんこ
11935	AtCoder CODE-FESTIVAL-2015-MORNING-HARD: C. 数列の組み替え
11934	AtCoder CODE-FESTIVAL-2015-MORNING-MIDDLE: D. 立方体とペンキ
11933	AtCoder CODE-FESTIVAL-2015-MORNING-MIDDLE: C. 一次元オセロ
11932	AtCoder CODE-FESTIVAL-2015-MORNING-EASY: D. ヘイホー君と削除
11931	AtCoder CODE-FESTIVAL-2015-MORNING-EASY: C. ヘイホー君と最終試験
11930	AtCoder CODE-FESTIVAL-2015-MORNING-EASY: B. ヘイホー君と置き換え
11929	AtCoder CODE-FESTIVAL-2015-MORNING-EASY: A. ヘイホー君と加算
11928	AtCoder CF17-FINAL: J. Tree MST
11927	AtCoder CF17-FINAL: I. Full Tournament
11926	AtCoder CF17-FINAL: H. Poor Penguin
11925	AtCoder CF17-FINAL: G. Mancala
11924	AtCoder CF17-FINAL: F. Distribute Numbers
11923	AtCoder CF17-FINAL: E. Combination Lock
11922	AtCoder CF17-FINAL: D. Zabuton
11921	AtCoder CF17-FINAL: C. Time Gap
11920	AtCoder CF17-FINAL: B. Palindrome-phobia
11919	AtCoder CF17-FINAL: A. AKIBA
11918	AtCoder CF17-EXHIBITION-OPEN: B. Increment and Swap
11917	AtCoder CF17-EXHIBITION-OPEN: A. Awkward
11916	AtCoder CF16-EXHIBITION-FINAL: J. 123 Pairs
11915	AtCoder CF16-EXHIBITION-FINAL: I. 90 and 270
11914	AtCoder CF16-EXHIBITION-FINAL: H. AB=C Problem
11913	AtCoder CF16-EXHIBITION-FINAL: G. FESTIVAL
11912	AtCoder CF16-EXHIBITION-FINAL: F. Intervals
11911	AtCoder CF16-EXHIBITION-FINAL: E. Water Distribution
11910	AtCoder CF16-EXHIBITION-FINAL: D. Dice Game
11909	AtCoder CF16-EXHIBITION-FINAL: C. Cheating Nim
11908	AtCoder CF16-EXHIBITION-FINAL: B. Inscribed Bicycle
11907	AtCoder CF16-EXHIBITION-FINAL: A. 1D Matching
11906	AtCoder CADDI2019: A. 球の詰め込み
11905	AtCoder CADDI2018B: B. AtCoder Alloy
11904	AtCoder CADDI2018B: A. 12/22
11903	AtCoder CADDI2018: F. Square
11902	AtCoder CADDI2018: E. Negative Doubling

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

11951

AtCoder CHOKUDAI001: A. 高橋君の山崩しゲーム

11950

AtCoder CHOKUDAI005: A. カラフルパネル

11949

AtCoder CHOKUDAI004: A. Just Write Numbers!

11948

AtCoder CHOKUDAI003: A. ○×ブロック

11947

AtCoder CHOKUDAI002: A. 約数をたくさんつくろう！

11946