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)
9451	AtCoder ABC153: E. Crested Ibis vs Monster
9450	AtCoder ABC153: D. Caracal vs Monster
9449	AtCoder ABC153: C. Fennec vs Monster
9448	AtCoder ABC153: B. Common Raccoon vs Monster
9447	AtCoder ABC153: A. Serval vs Monster
9446	AtCoder ABC152: F. Tree and Constraints
9445	AtCoder ABC152: E. Flatten
9444	AtCoder ABC152: D. Handstand 2
9443	AtCoder ABC152: C. Low Elements
9442	AtCoder ABC152: B. Comparing Strings
9441	AtCoder ABC152: A. AC or WA
9440	AtCoder ABC151: F. Enclose All
9439	AtCoder ABC151: E. Max-Min Sums
9438	AtCoder ABC151: D. Maze Master
9437	AtCoder ABC151: C. Welcome to AtCoder
9436	AtCoder ABC151: B. Achieve the Goal
9435	AtCoder ABC151: A. Next Alphabet
9434	AtCoder ABC150: F. Xor Shift
9433	AtCoder ABC150: E. Change a Little Bit
9432	AtCoder ABC150: D. Semi Common Multiple
9431	AtCoder ABC150: C. Count Order
9430	AtCoder ABC150: B. Count ABC
9429	AtCoder ABC150: A. 500 Yen Coins
9428	AtCoder ABC149: F. Surrounded Nodes
9427	AtCoder ABC149: E. Handshake
9426	AtCoder ABC149: D. Prediction and Restriction
9425	AtCoder ABC149: C. Next Prime
9424	AtCoder ABC149: B. Greedy Takahashi
9423	AtCoder ABC149: A. Strings
9422	AtCoder ABC148: F. Playing Tag on Tree
9421	AtCoder ABC148: E. Double Factorial
9420	AtCoder ABC148: D. Brick Break
9419	AtCoder ABC148: C. Snack
9418	AtCoder ABC148: B. Strings with the Same Length
9417	AtCoder ABC148: A. Round One
9416	AtCoder ABC147: F. Sum Difference
9415	AtCoder ABC147: E. Balanced Path
9414	AtCoder ABC147: D. Xor Sum 4
9413	AtCoder ABC147: C. HonestOrUnkind2
9412	AtCoder ABC147: B. Palindrome-philia
9411	AtCoder ABC147: A. Blackjack
9410	AtCoder ABC146: F. Sugoroku
9409	AtCoder ABC146: E. Rem of Sum is Num
9408	AtCoder ABC146: D. Coloring Edges on Tree
9407	AtCoder ABC146: C. Buy an Integer
9406	AtCoder ABC146: B. ROT N
9405	AtCoder ABC146: A. Can't Wait for Holiday
9404	AtCoder ABC145: F. Laminate
9403	AtCoder ABC145: E. All-you-can-eat
9402	AtCoder ABC145: D. Knight

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

9451

AtCoder ABC153: E. Crested Ibis vs Monster

9450

AtCoder ABC153: D. Caracal vs Monster

9449

AtCoder ABC153: C. Fennec vs Monster

9448

AtCoder ABC153: B. Common Raccoon vs Monster

9447

AtCoder ABC153: A. Serval vs Monster

9446