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)
11801	AtCoder ARC158: E. All Pair Shortest Paths
11800	AtCoder ARC158: D. Equation
11799	AtCoder ARC158: C. All Pair Digit Sums
11798	AtCoder ARC158: B. Sum-Product Ratio
11797	AtCoder ARC158: A. +3 +5 +7
11796	AtCoder ARC157: F. XY Ladder LCS
11795	AtCoder ARC157: E. XXYX Binary Tree
11794	AtCoder ARC157: D. YY Garden
11793	AtCoder ARC157: C. YY Square
11792	AtCoder ARC157: B. XYYYX
11791	AtCoder ARC157: A. XXYYX
11790	AtCoder ARC156: F. Make Same Set
11789	AtCoder ARC156: E. Non-Adjacent Matching
11788	AtCoder ARC156: D. Xor Sum 5
11787	AtCoder ARC156: C. Tree and LCS
11786	AtCoder ARC156: B. Mex on Blackboard
11785	AtCoder ARC156: A. Non-Adjacent Flip
11784	AtCoder ARC155: F. Directable as Desired
11783	AtCoder ARC155: E. Split and Square
11782	AtCoder ARC155: D. Avoid Coprime Game
11781	AtCoder ARC155: C. Even Sum Triplet
11780	AtCoder ARC155: B. Abs Abs Function
11779	AtCoder ARC155: A. ST and TS Palindrome
11778	AtCoder ARC154: F. Dice Game
11777	AtCoder ARC154: E. Reverse and Inversion
11776	AtCoder ARC154: D. A + B > C ?
11775	AtCoder ARC154: C. Roller
11774	AtCoder ARC154: B. New Place
11773	AtCoder ARC154: A. Swap Digit
11772	AtCoder ARC153: F. Tri-Colored Paths
11771	AtCoder ARC153: E. Deque Minimization
11770	AtCoder ARC153: D. Sum of Sum of Digits
11769	AtCoder ARC153: C. ± Increasing Sequence
11768	AtCoder ARC153: B. Grid Rotations
11767	AtCoder ARC153: A. AABCDDEFE
11766	AtCoder ARC152: F. Attraction on Tree
11765	AtCoder ARC152: E. Xor Annihilation
11764	AtCoder ARC152: D. Halftree
11763	AtCoder ARC152: C. Pivot
11762	AtCoder ARC152: B. Pass on Path
11761	AtCoder ARC152: A. Seat Occupation
11760	AtCoder ARC151: F. RGB Card Game
11759	AtCoder ARC151: E. Keep Being Substring
11758	AtCoder ARC151: D. Binary Representations and Queries
11757	AtCoder ARC151: C. 01 Game
11756	AtCoder ARC151: B. A < AP
11755	AtCoder ARC151: A. Equal Hamming Distances
11754	AtCoder ARC150: F. Constant Sum Subsequence
11753	AtCoder ARC150: E. Weathercock
11752	AtCoder ARC150: D. Removing Gacha

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

11801

AtCoder ARC158: E. All Pair Shortest Paths

11800

AtCoder ARC158: D. Equation

11799

AtCoder ARC158: C. All Pair Digit Sums

11798

AtCoder ARC158: B. Sum-Product Ratio

11797

AtCoder ARC158: A. +3 +5 +7

11796