### mohabamr's blog

By mohabamr, history, 23 months ago, ,

Hello guys, for those of you who are tired of searching for "what to solve next", my bachelor thesis was to implement a recommender system for competitive programming problems; supervised by Dr. Amr ElMougy and Maged Shalaby

Give it a look and check your recommendations now: https://acm-recommender.herokuapp.com/#/signup

Sign-up (using your codeforces username) then sign-in and check your recommendations in almost no time (just give it a minute or 2).

There would be 10 problems recommended per user, we encourage you to solve them and give us feedback about each recommendation (through the "evaluate" button).

It is very important to evaluate the problems, as this feedback is needed to enhance the recommender and conclude which algorithm is better. So, please don't forget to submit your evaluations!

Thank you and happy coding.

For any problems or suggestions; you can contact me: mohabamr1@gmail.com

• +65

 » 23 months ago, # |   +3 Application error
•  » » 23 months ago, # ^ |   0 please, check now.Heroku crashes sometimes and restarts automatically.
•  » » » 23 months ago, # ^ |   0 Yep, now it works.
 » 23 months ago, # |   +12 How exactly do you calculate what problems to recommend?
•  » » 23 months ago, # ^ |   0 it's a hybrid approach of Collborative filtering and another layer to filter out the most relatable problems (tags) to your history.
 » 23 months ago, # |   +3 It would be really great if it was possible to hide a problem from the list after you solved and evaluated it.
•  » » 23 months ago, # ^ |   0 you're totally right, would do that in the next release. soon.
•  » » 23 months ago, # ^ |   +3 I still did not submit it, it's a hybrid approach between CF (user-based) and some filtering regarding the tags and difficulty level of the problem.I will try to publish it if possible.
 » 23 months ago, # |   +3 My recommendations are not generated yet, so, i'll be back
•  » » 23 months ago, # ^ |   +1 Same here, I have waited like 20 minutes already.
•  » » » 23 months ago, # ^ |   0 I am sorry this happened, but I made sure your recommendations are available now.please, check and evaluate.https://acm-recommender.herokuapp.com
•  » » 23 months ago, # ^ |   0 don't forget to check again
•  » » » 23 months ago, # ^ |   0 Hmm, if the system recommends me problems for the first division, does this mean that I'm ready for the first division?
•  » » » » 23 months ago, # ^ |   0 not exactly, but most probably yes.the system recommends for you problems that should be a little bit harder than the usual to challenge your skills, but at the same time in a certain range so you would not be frustrated.
 » 23 months ago, # |   0 Interesting Idea!
•  » » 23 months ago, # ^ |   0 thanks, have you tried it?
 » 23 months ago, # |   0 Auto comment: topic has been updated by mohabamr (previous revision, new revision, compare).
 » 23 months ago, # |   0 So we can use this to find duplicate problems?
•  » » 23 months ago, # ^ |   0 nope, problems you did not solve, assuming.
•  » » » 23 months ago, # ^ |   +17 It gave me a problem I solved already: 752B. Maybe because the problem occurs in different contests: (Technocup Div.2, Technocup Div. 1, and official Technocup). Can you look into this? thanks
 » 23 months ago, # | ← Rev. 2 →   +3 It would be better if it was possible to change recommendations (it's showing easier problems :) ). What can I do if I need harder problems?
 » 23 months ago, # |   0 Auto comment: topic has been updated by mohabamr (previous revision, new revision, compare).
 » 23 months ago, # |   +5 have done all the problems but no new recommendsis that a bug ?
•  » » 23 months ago, # ^ |   +5 nope, the beta version allows you only 10 static problems, but very soon I am gonna change this.
 » 23 months ago, # |   0 Hey,can you please provide a way to generate team recommendations for ICPC practice? That would be great.
•  » » 23 months ago, # ^ |   0 that's a great idea, promise you I will work on that.
 » 23 months ago, # |   0 It recommended me problems that I already solved on the other division.
•  » » 23 months ago, # ^ |   0 Next release will handle such bug
 » 23 months ago, # |   0 why am i facing this ?
•  » » 23 months ago, # ^ |   0 Codeforces itself crashed for a while, I don't know if this is related.When did you face such an error?
•  » » » 23 months ago, # ^ |   0 I having a problem with recommendation issue . After a while its ok , it successfully retreived the recommended problems .
•  » » » » 23 months ago, # ^ |   0 I recommend anyone who had a problem to try again, it's just the server's load is too much.
 » 23 months ago, # |   +3 Currently, anyone with a person username and email(easy to get) can access it with his choice of password. This way the original person can't access his own account.
•  » » 23 months ago, # ^ |   0 I know there is no way of validating, but the original purpose for this website was for a small team to use, I did not expect people would interacte with it like that.Anyway: If anyone faces a problem; they can contact me so I can validate the users myself for now I will see if I can validate the email with the username from Codeforces API
•  » » » 23 months ago, # ^ |   0 just a question, why do you even need a login for your website? why can't user just provide their username to see the recommendations?
•  » » » » 23 months ago, # ^ |   0 a basic auth tool to be used later needed in the evaluation section, to make sure it's the same user email to send notifications
 » 23 months ago, # | ← Rev. 2 →   0 what if i solved 10 problems,will it show next 10 problems??
•  » » 23 months ago, # ^ |   0 not just yet, but very soon this feature will be available.
•  » » » 23 months ago, # ^ | ← Rev. 2 →   0 Danke,Nice Work btw :)
 » 23 months ago, # |   0 Its only showing me div2 A,B,Cs. Anyway I can get harder problems?
•  » » 23 months ago, # ^ |   0 The output is based on your solving history.Anyway, the re-generation of the recommendation set is a feature I am working on, the next release will be out in 10 days or so.
 » 23 months ago, # |   0 The character '| in my username is not supported :p Can't sign up.
•  » » 23 months ago, # ^ |   0 I just tested that and it's working fine, please try again or DM me your info so I can create an account for you.
 » 6 weeks ago, # |   +7 I just tried it and it showed Something went wrong: 503 at this page: https://acm-recommender.herokuapp.com/#/recommendations :(
•  » » 6 weeks ago, # ^ |   0 I will check it and get back to you guys
•  » » » 6 weeks ago, # ^ |   0 Thanks!
 » 6 weeks ago, # |   +3 Its not working.
•  » » 6 weeks ago, # ^ |   0 can you at least register and login?Is the crash related to the recommendations part only or to all functionalities of the website?
•  » » » 6 weeks ago, # ^ | ← Rev. 2 →   0 Hey, it's not working, as has been stated by many people above. The error is message is like so ErrorSomething went wrong: 503 * 0 : < * 1 : ! * 2 : D * 3 : O * 4 : C * 5 : T * 6 : Y * 7 : P * 8 : E * 9 : * 10 : h * 11 : t * 12 : m * 13 : l * 14 : > * 15 : * 16 : * 17 : < * 18 : h * 19 : t * 20 : m * 21 : l * 22 : > * 23 : * 24 : * 25 : * 26 : * 27 : < * 28 : h * 29 : e * 30 : a * 31 : d * 32 : > * 33 : * 34 : * 35 : * 36 : < * 37 : m * 38 : e * 39 : t * 40 : a * 41 : * 42 : n * 43 : a * 44 : m * 45 : e * 46 : = * 47 : " * 48 : v * 49 : i * 50 : e * 51 : w * 52 : p * 53 : o * 54 : r * 55 : t * 56 : " * 57 : * 58 : c * 59 : o * 60 : n * 61 : t * 62 : e * 63 : n * 64 : t * 65 : = * 66 : " * 67 : w * 68 : i * 69 : d * 70 : t * 71 : h * 72 : = * 73 : d * 74 : e * 75 : v * 76 : i * 77 : c * 78 : e * 79 : - * 80 : w * 81 : i * 82 : d * 83 : t * 84 : h * 85 : , * 86 : * 87 : i * 88 : n * 89 : i * 90 : t * 91 : i * 92 : a * 93 : l * 94 : - * 95 : s * 96 : c * 97 : a * 98 : l * 99 : e * 100 : = * 101 : 1 * 102 : " * 103 : > * 104 : * 105 : * 106 : * 107 : < * 108 : m * 109 : e * 110 : t * 111 : a * 112 : * 113 : c * 114 : h * 115 : a * 116 : r * 117 : s * 118 : e * 119 : t * 120 : = * 121 : " * 122 : u * 123 : t * 124 : f * 125 : - * 126 : 8 * 127 : " * 128 : > * 129 : * 130 : * 131 : * 132 : < * 133 : t * 134 : i * 135 : t * 136 : l * 137 : e * 138 : > * 139 : A * 140 : p * 141 : p * 142 : l * 143 : i * 144 : c * 145 : a * 146 : t * 147 : i * 148 : o * 149 : n * 150 : * 151 : E * 152 : r * 153 : r * 154 : o * 155 : r * 156 : < * 157 : / * 158 : t * 159 : i * 160 : t * 161 : l * 162 : e * 163 : > * 164 : * 165 : * 166 : * 167 : < * 168 : s * 169 : t * 170 : y * 171 : l * 172 : e * 173 : * 174 : m * 175 : e * 176 : d * 177 : i * 178 : a * 179 : = * 180 : " * 181 : s * 182 : c * 183 : r * 184 : e * 185 : e * 186 : n * 187 : " * 188 : > * 189 : * 190 : * 191 : * 192 : * 193 : * 194 : h * 195 : t * 196 : m * 197 : l * 198 : , * 199 : b * 200 : o * 201 : d * 202 : y * 203 : , * 204 : i * 205 : f * 206 : r * 207 : a * 208 : m * 209 : e * 210 : * 211 : { * 212 : * 213 : * 214 : * 215 : * 216 : m * 217 : a * 218 : r * 219 : g * 220 : i * 221 : n * 222 : : * 223 : * 224 : 0 * 225 : ; * 226 : * 227 : * 228 : * 229 : * 230 : p * 231 : a * 232 : d * 233 : d * 234 : i * 235 : n * 236 : g * 237 : : * 238 : * 239 : 0 * 240 : ; * 241 : * 242 : * 243 : * 244 : * 245 : * 246 : } * 247 : * 248 : * 249 : * 250 : * 251 : * 252 : h * 253 : t * 254 : m * 255 : l * 256 : , * 257 : b * 258 : o * 259 : d * 260 : y * 261 : * 262 : { * 263 : * 264 : * 265 : * 266 : * 267 : h * 268 : e * 269 : i * 270 : g * 271 : h * 272 : t * 273 : : * 274 : * 275 : 1 * 276 : 0 * 277 : 0 * 278 : % * 279 : ; * 280 : * 281 : * 282 : * 283 : * 284 : o * 285 : v * 286 : e * 287 : r * 288 : f * 289 : l * 290 : o * 291 : w * 292 : : * 293 : * 294 : h * 295 : i * 296 : d * 297 : d * 298 : e * 299 : n * 300 : ; * 301 : * 302 : * 303 : * 304 : * 305 : * 306 : } * 307 : * 308 : * 309 : * 310 : * 311 : * 312 : i * 313 : f * 314 : r * 315 : a * 316 : m * 317 : e * 318 : * 319 : { * 320 : * 321 : * 322 : * 323 : * 324 : w * 325 : i * 326 : d * 327 : t * 328 : h * 329 : : * 330 : * 331 : 1 * 332 : 0 * 333 : 0 * 334 : % * 335 : ; * 336 : * 337 : * 338 : * 339 : * 340 : h * 341 : e * 342 : i * 343 : g * 344 : h * 345 : t * 346 : : * 347 : * 348 : 1 * 349 : 0 * 350 : 0 * 351 : % * 352 : ; * 353 : * 354 : * 355 : * 356 : * 357 : b * 358 : o * 359 : r * 360 : d * 361 : e * 362 : r * 363 : : * 364 : * 365 : 0 * 366 : ; * 367 : * 368 : * 369 : * 370 : * 371 : * 372 : } * 373 : * 374 : * 375 : * 376 : < * 377 : / * 378 : s * 379 : t * 380 : y * 381 : l * 382 : e * 383 : > * 384 : * 385 : * 386 : * 387 : * 388 : < * 389 : / * 390 : h * 391 : e * 392 : a * 393 : d * 394 : > * 395 : * 396 : * 397 : * 398 : * 399 : < * 400 : b * 401 : o * 402 : d * 403 : y * 404 : > * 405 : * 406 : * 407 : * 408 : < * 409 : i * 410 : f * 411 : r * 412 : a * 413 : m * 414 : e * 415 : * 416 : s * 417 : r * 418 : c * 419 : = * 420 : " * 421 : / * 422 : / * 423 : w * 424 : w * 425 : w * 426 : . * 427 : h * 428 : e * 429 : r * 430 : o * 431 : k * 432 : u * 433 : c * 434 : d * 435 : n * 436 : . * 437 : c * 438 : o * 439 : m * 440 : / * 441 : e * 442 : r * 443 : r * 444 : o * 445 : r * 446 : - * 447 : p * 448 : a * 449 : g * 450 : e * 451 : s * 452 : / * 453 : a * 454 : p * 455 : p * 456 : l * 457 : i * 458 : c * 459 : a * 460 : t * 461 : i * 462 : o * 463 : n * 464 : - * 465 : e * 466 : r * 467 : r * 468 : o * 469 : r * 470 : . * 471 : h * 472 : t * 473 : m * 474 : l * 475 : " * 476 : > * 477 : < * 478 : / * 479 : i * 480 : f * 481 : r * 482 : a * 483 : m * 484 : e * 485 : > * 486 : * 487 : * 488 : * 489 : * 490 : < * 491 : / * 492 : b * 493 : o * 494 : d * 495 : y * 496 : > * 497 : * 498 : * 499 : < * 500 : / * 501 : h * 502 : t * 503 : m * 504 : l * 505 : >
•  » » » » 6 weeks ago, # ^ |   0 Yeah, the project is almost 2 years old. I am just trying to get down to the actual bug, which pages crash or don't work properly. because it works fine when I sign with my username but maybe that's because my data is already aggregated.The actual needed steps: Register Login Wait for recommendations Evaluate Recommendations
 » 6 weeks ago, # |   +3 Something went wrong: 503 :(
 » 6 weeks ago, # |   0 It says something went wrong