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)
14051	AtCoder PAST202303-OPEN: J. 図形のシフト
14050	AtCoder PAST202303-OPEN: I. 簡易オマハポーカー
14049	AtCoder PAST202303-OPEN: H. 3 枚階段
14048	AtCoder PAST202303-OPEN: G. 隣り合うマス
14047	AtCoder PAST202303-OPEN: F. 集合の問題
14046	AtCoder PAST202303-OPEN: E. 図形のシャッフル
14045	AtCoder PAST202303-OPEN: D. シューティング
14044	AtCoder PAST202303-OPEN: C. 逆順列
14043	AtCoder PAST202303-OPEN: B. 小数点第 D 位
14042	AtCoder PAST202303-OPEN: A. シンプル石取りゲーム
14041	AtCoder PAST202212-OPEN: O. Shift and Shift
14040	AtCoder PAST202212-OPEN: N. Sequence and Function
14039	AtCoder PAST202212-OPEN: M. Tree and Intervals
14038	AtCoder PAST202212-OPEN: L. Segments
14037	AtCoder PAST202212-OPEN: K. Buy an Integer
14036	AtCoder PAST202212-OPEN: J. Crossing
14035	AtCoder PAST202212-OPEN: I. Order of Height
14034	AtCoder PAST202212-OPEN: H. Digit Diff Sum
14033	AtCoder PAST202212-OPEN: G. Range Sum
14032	AtCoder PAST202212-OPEN: F. Average Ranking
14031	AtCoder PAST202212-OPEN: E. Parentheses
14030	AtCoder PAST202212-OPEN: D. Bozu Mekuri
14029	AtCoder PAST202212-OPEN: C. Triplet Product
14028	AtCoder PAST202212-OPEN: B. Fractional Comparison
14027	AtCoder PAST202212-OPEN: A. Tokens
14026	AtCoder PAST202209-OPEN: O. Pick Two Numbers
14025	AtCoder PAST202209-OPEN: N. From Above and From the Side
14024	AtCoder PAST202209-OPEN: M. series
14023	AtCoder PAST202209-OPEN: L. Exhibition
14022	AtCoder PAST202209-OPEN: K. Checking Connectivity
14021	AtCoder PAST202209-OPEN: J. Sprinkler
14020	AtCoder PAST202209-OPEN: I. Buying Apple Everyday
14019	AtCoder PAST202209-OPEN: H. Three Types of Coins
14018	AtCoder PAST202209-OPEN: G. Wildcards
14017	AtCoder PAST202209-OPEN: F. Pharmacist
14016	AtCoder PAST202209-OPEN: E. Hitting Stick Game
14015	AtCoder PAST202209-OPEN: D. Marking
14014	AtCoder PAST202209-OPEN: C. Biased Dice
14013	AtCoder PAST202209-OPEN: B. Credits
14012	AtCoder PAST202209-OPEN: A. Trafic Light
14011	AtCoder PAST202206-OPEN: O. Area Queries
14010	AtCoder PAST202206-OPEN: N. Building Plan
14009	AtCoder PAST202206-OPEN: M. Reversal
14008	AtCoder PAST202206-OPEN: L. Almost LCS
14007	AtCoder PAST202206-OPEN: K. Subsequence
14006	AtCoder PAST202206-OPEN: J. Holidays
14005	AtCoder PAST202206-OPEN: I. Clean up
14004	AtCoder PAST202206-OPEN: H. Two Knapsacks
14003	AtCoder PAST202206-OPEN: G. Is it a tree?
14002	AtCoder PAST202206-OPEN: F. Gun Shooting

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

14051

AtCoder PAST202303-OPEN: J. 図形のシフト

14050

AtCoder PAST202303-OPEN: I. 簡易オマハポーカー

14049

AtCoder PAST202303-OPEN: H. 3 枚階段

14048

AtCoder PAST202303-OPEN: G. 隣り合うマス

14047

AtCoder PAST202303-OPEN: F. 集合の問題

14046