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)
13351	AtCoder KEYENCE2020: B. Robot Arms
13350	AtCoder KEYENCE2020: A. Painting
13349	AtCoder KEYENCE2019: F. Paper Cutting
13348	AtCoder KEYENCE2019: E. Connecting Cities
13347	AtCoder KEYENCE2019: D. Double Landscape
13346	AtCoder KEYENCE2019: C. Exam and Wizard
13345	AtCoder KEYENCE2019: B. KEYENCE String
13344	AtCoder KEYENCE2019: A. Beginning
13343	AtCoder K4PC: G. 42
13342	AtCoder K4PC: F. タイトル未定(Untitled)
13341	AtCoder K4PC: E. はじめての動的計画法(Easy Dynamic Programming)
13340	AtCoder K4PC: D. たのしい運動会(School Sports is Fun)
13339	AtCoder K4PC: C. 山登り(Mountain Climbing)
13338	AtCoder K4PC: B. コミュニケーション能力(Communication Ability)
13337	AtCoder K4PC: A. ブロックの移動(Blocks)
13336	AtCoder K2PC-HARD: E. 暗号化(Encipherment)
13335	AtCoder K2PC-HARD: D. マシュマロ(Marshmallow)
13334	AtCoder K2PC-HARD: C. お気に入りの数2(Favorite Number2)
13333	AtCoder K2PC-HARD: B. 虫歯(Cavity)
13332	AtCoder K2PC-HARD: A. 紅茶(Tea)
13331	AtCoder K2PC-EASY: E. お気に入りの数2(Favorite Number2)
13330	AtCoder K2PC-EASY: D. 虫歯(Cavity)
13329	AtCoder K2PC-EASY: C. 紅茶(Tea)
13328	AtCoder K2PC-EASY: B. ビットマニア(BITMANIA)
13327	AtCoder K2PC-EASY: A. ハンバーガー(Hamburger)
13326	AtCoder JUDGE-UPDATE-202004: D. Calculating GCD
13325	AtCoder JUDGE-UPDATE-202004: C. Numbering Blocks
13324	AtCoder JUDGE-UPDATE-202004: B. Picking Balls
13323	AtCoder JUDGE-UPDATE-202004: A. Walking Takahashi
13322	AtCoder JSC2022-FINAL-OPEN: G. Bipartite Partition
13321	AtCoder JSC2022-FINAL-OPEN: F. Share the Recipe
13320	AtCoder JSC2022-FINAL-OPEN: E. Circular Sushi
13319	AtCoder JSC2022-FINAL-OPEN: D. And is 0
13318	AtCoder JSC2022-FINAL-OPEN: C. Not a Multiple of 3
13317	AtCoder JSC2022-FINAL-OPEN: B. Increment and Rotate
13316	AtCoder JSC2022-FINAL-OPEN: A. Max and Argmax
13315	AtCoder JSC2021: H. Shipping
13314	AtCoder JSC2021: G. Spanning Tree
13313	AtCoder JSC2021: F. Max Matrix
13312	AtCoder JSC2021: E. Level K Palindrome
13311	AtCoder JSC2021: D. Nowhere P
13310	AtCoder JSC2021: C. Max GCD 2
13309	AtCoder JSC2021: B. Xor of Sequences
13308	AtCoder JSC2021: A. Competition
13307	AtCoder JSC2019-QUAL: F. Candy Retribution
13306	AtCoder JSC2019-QUAL: E. Card Collector
13305	AtCoder JSC2019-QUAL: D. Classified
13304	AtCoder JSC2019-QUAL: C. Cell Inversion
13303	AtCoder JSC2019-QUAL: B. Kleene Inversion
13302	AtCoder JSC2019-QUAL: A. Takahashi Calendar

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

13351

AtCoder KEYENCE2020: B. Robot Arms

13350

AtCoder KEYENCE2020: A. Painting

13349

AtCoder KEYENCE2019: F. Paper Cutting

13348

AtCoder KEYENCE2019: E. Connecting Cities

13347

AtCoder KEYENCE2019: D. Double Landscape

13346