Starlight

Over 20,000 problems available: AMC 8/10/12 and AIME problems from 2010-2024; USAJMO/USAMO problems from 2002-2024; USACO problems from 2014 to 2024 (all divisions); all Codeforces, AtCoder and DMOJ problems. If you leave the search field blank, it returns all problems with the specified type.

Reset

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)
3550 Codeforces 835C: Star sky
3549 Codeforces 835B: The number on the board
3548 Codeforces 835A: Key races
3547 Codeforces 834B: The Festive Evening
3546 Codeforces 834A: The Useless Toy
3545 Codeforces 833E: Caramel Clouds
3544 Codeforces 833D: Red-Black Cobweb
3543 Codeforces 833C: Ever-Hungry Krakozyabra
3542 Codeforces 833B: The Bakery
3541 Codeforces 833A: The Meaningless Game
3540 Codeforces 832E: Vasya and Shifts
3539 Codeforces 832D: Misha, Grisha and Underground
3538 Codeforces 832C: Strange Radiation
3537 Codeforces 832B: Petya and Exam
3536 Codeforces 832A: Sasha and Sticks
3535 Codeforces 831C: Jury Marks
3534 Codeforces 831B: Keyboard Layouts
3533 Codeforces 831A: Unimodal Array
3532 Codeforces 830E: Perpetual Motion Machine
3531 Codeforces 830D: Singer House
3530 Codeforces 830C: Bamboo Partition
3529 Codeforces 830B: Cards Sorting
3528 Codeforces 830A: Office Keys
3527 Codeforces 828B: Black Square
3526 Codeforces 828A: Restaurant Tables
3525 Codeforces 827F: Dirty Arkady's Kitchen
3524 Codeforces 827E: Rusty String
3523 Codeforces 827D: Best Edge Weight
3522 Codeforces 827C: DNA Evolution
3521 Codeforces 827B: High Load
3520 Codeforces 827A: String Reconstruction
3519 Codeforces 825G: Tree Queries
3518 Codeforces 825F: String Compression
3517 Codeforces 825E: Minimal Labels
3516 Codeforces 825D: Suitable Replacement
3515 Codeforces 825C: Multi-judge Solving
3514 Codeforces 825B: Five-In-a-Row
3513 Codeforces 825A: Binary Protocol
3512 Codeforces 822F: Madness
3511 Codeforces 822E: Liar
3510 Codeforces 822D: My pretty girl Noora
3509 Codeforces 822C: Hacker, pack your bags!
3508 Codeforces 822B: Crossword solving
3507 Codeforces 822A: I'm bored with life
3506 Codeforces 821E: Okabe and El Psy Kongroo
3505 Codeforces 821D: Okabe and City
3504 Codeforces 821C: Okabe and Boxes
3503 Codeforces 821B: Okabe and Banana Trees
3502 Codeforces 821A: Okabe and Future Gadget Laboratory
3501 Codeforces 820B: Mister B and Angle in Polygon
View links to all pages 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192

About • Privacy Notice • Rules • Problems list • Journal • Your profile • GitHub

Moon Symbol icon by Icons8 • Sun icon by Icons8 • Emojis from Twemoji by Twitter under CC by 4.0