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)
7955 Codeforces 1710A: Color the Picture
7954 Codeforces 1709F: Multiset of Strings
7953 Codeforces 1709E: XOR Tree
7952 Codeforces 1709D: Rorororobot
7951 Codeforces 1709C: Recover an RBS
7950 Codeforces 1709B: Also Try Minecraft
7949 Codeforces 1709A: Three Doors
7948 Codeforces 1708B: Difference of GCDs
7947 Codeforces 1708A: Difference Operations
7946 Codeforces 1707F: Bugaboo
7945 Codeforces 1707E: Replace
7944 Codeforces 1707D: Partial Virtual Trees
7943 Codeforces 1707C: DFS Trees
7942 Codeforces 1707B: Difference Array
7941 Codeforces 1707A: Doremy's IQ
7940 Codeforces 1706E: Qpwoeirut and Vertices
7939 Codeforces 1706D2: Chopping Carrots (Hard Version)
7938 Codeforces 1706D1: Chopping Carrots (Easy Version)
7937 Codeforces 1706C: Qpwoeirut And The City
7936 Codeforces 1706B: Making Towers
7935 Codeforces 1706A: Another String Minimization Problem
7934 Codeforces 1705F: Mark and the Online Exam
7933 Codeforces 1705E: Mark and Professor Koro
7932 Codeforces 1705D: Mark and Lightbulbs
7931 Codeforces 1705C: Mark and His Unfinished Essay
7930 Codeforces 1705B: Mark the Dust Sweeper
7929 Codeforces 1705A: Mark the Photographer
7928 Codeforces 1704H2: Game of AI (hard version)
7927 Codeforces 1704H1: Game of AI (easy version)
7926 Codeforces 1704G: Mio and Lucky Array
7925 Codeforces 1704F: Colouring Game
7924 Codeforces 1704E: Count Seconds
7923 Codeforces 1704D: Magical Array
7922 Codeforces 1704C: Virus
7921 Codeforces 1704B: Luke is a Foodie
7920 Codeforces 1704A: Two 0-1 Sequences
7919 Codeforces 1703G: Good Key, Bad Key
7918 Codeforces 1703F: Yet Another Problem About Pairs Satisfying an Inequality
7917 Codeforces 1703E: Mirror Grid
7916 Codeforces 1703D: Double Strings
7915 Codeforces 1703C: Cypher
7914 Codeforces 1703B: ICPC Balloons
7913 Codeforces 1703A: YES or YES?
7912 Codeforces 1702G2: Passable Paths (hard version)
7911 Codeforces 1702G1: Passable Paths (easy version)
7910 Codeforces 1702F: Equate Multisets
7909 Codeforces 1702E: Split Into Two Sets
7908 Codeforces 1702D: Not a Cheap String
7907 Codeforces 1702C: Train and Queries
7906 Codeforces 1702B: Polycarp Writes a String from Memory
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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514

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