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)
11651	AtCoder ARC133: E. Cyclic Medians
11650	AtCoder ARC133: D. Range XOR
11649	AtCoder ARC133: C. Row Column Sums
11648	AtCoder ARC133: B. Dividing Subsequence
11647	AtCoder ARC133: A. Erase by Value
11646	AtCoder ARC132: F. Takahashi The Strongest
11645	AtCoder ARC132: E. Paw
11644	AtCoder ARC132: D. Between Two Binary Strings
11643	AtCoder ARC132: C. Almost Sorted
11642	AtCoder ARC132: B. Shift and Reverse
11641	AtCoder ARC132: A. Permutation Grid
11640	AtCoder ARC131: F. ARC Stamp
11639	AtCoder ARC131: E. Christmas Wreath
11638	AtCoder ARC131: D. AtArcher
11637	AtCoder ARC131: C. Zero XOR
11636	AtCoder ARC131: B. Grid Repainting 4
11635	AtCoder ARC131: A. Two Lucky Numbers
11634	AtCoder ARC130: F. Replace by Average
11633	AtCoder ARC130: E. Increasing Minimum
11632	AtCoder ARC130: D. Zigzag Tree
11631	AtCoder ARC130: C. Digit Sum Minimization
11630	AtCoder ARC130: B. Colorful Lines
11629	AtCoder ARC130: A. Remove One Character
11628	AtCoder ARC129: F. Let's Play Tag
11627	AtCoder ARC129: E. Yet Another Minimization
11626	AtCoder ARC129: D. -1+2-1
11625	AtCoder ARC129: C. Multiple of 7
11624	AtCoder ARC129: B. Range Point Distance
11623	AtCoder ARC129: A. Smaller XOR
11622	AtCoder ARC128: F. Game against Robot
11621	AtCoder ARC128: E. K Different Values
11620	AtCoder ARC128: D. Neq Neq
11619	AtCoder ARC128: C. Max Dot
11618	AtCoder ARC128: B. Balls of Three Colors
11617	AtCoder ARC128: A. Gold and Silver
11616	AtCoder ARC127: F. ±AB
11615	AtCoder ARC127: E. Priority Queue
11614	AtCoder ARC127: D. Sum of Min of Xor
11613	AtCoder ARC127: C. Binary Strings
11612	AtCoder ARC127: B. Ternary Strings
11611	AtCoder ARC127: A. Leading 1s
11610	AtCoder ARC126: F. Affine Sort
11609	AtCoder ARC126: E. Infinite Operations
11608	AtCoder ARC126: D. Pure Straight
11607	AtCoder ARC126: C. Maximize GCD
11606	AtCoder ARC126: B. Cross-free Matching
11605	AtCoder ARC126: A. Make 10
11604	AtCoder ARC125: F. Tree Degree Subset Sum
11603	AtCoder ARC125: E. Snack
11602	AtCoder ARC125: D. Unique Subsequence

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

11651

AtCoder ARC133: E. Cyclic Medians

11650

AtCoder ARC133: D. Range XOR

11649

AtCoder ARC133: C. Row Column Sums

11648

AtCoder ARC133: B. Dividing Subsequence

11647

AtCoder ARC133: A. Erase by Value

11646