This Document provides the selected team list for ICPC Regional 2020. THIS IS A TENTATIVE LIST. Currently, the hosts plan to accommodate all these teams in the contest. If, due to the demand of the extreme situation, the capacity is revised, then an updated list will be published. This year is extraordinary, and we appreciate your patience and support in organizing this event.

The document includes: 1. Report on the mistake of problem C 2. Report on the plagiarism charges 3. Updated rank-list 4. Selected team list Mistake on Problem C of ICPC Dhaka Regional 2020 Online Preliminary Contest A mistake was found in the judge data of Problem C (Almost a Palindrome) after the contest was over. Unfortunately, the mistake potentially harmed teams who approached it in the correct way. Thus, teams might have had a better rank than the one they achieved during the contest.

The Issue The core algorithm to solve the problem was correct in the setter’s, tester’s and two alternate writers’ solutions. But they all missed a corner case. The problem requires the smallest index in case of multiple possible answers and in this case, judges’ solution may produce an index which is not the smallest.

Handling this corner case requires a little addition after finding the answer with the core algorithm. Without handling this case, for some input the judges’ output was flawed. So, this mistake doesn’t affect the efficiency of the judges’ solution rather the correctness in this case.

The Resolve from Judges Judges did the following steps to resolve the issue. 1. We have created the correct output files based on the correct algorithm. Input files were unchanged. 2. We rejudged all the submissions which got “Wrong Answer” as a verdict during the contest. 3. We marked all the submissions which had a changed verdict after the rejudge. 4. The submissions which were accepted after the rejudge were used to update the rank-list. 5. The submissions which got “Time Limit Exceeded” after the rejudge were marked as “Significantly Affected”.

Judges Proposition The judges had a meeting on 9th April, 2021 (Friday) and they collectively decided that the teams with “Significantly Affected” verdict in problem C might have suffered during the contest due the mistake. The judges propose to resolve this by the following: ● Assume “Significantly Affected” submissions were accepted. ● Calculate rank-list based on that assumption. ● Calculating the list of selected teams for ICPC Dhaka Regional 2020 based on that rank-list.

Note 1. We did not change any input file. The teams didn’t have the chance to update their submissions after the contest is over, so modifying/adding new input is unfair to teams. 2. As the input files were unchanged, no submission other than “Wrong Answer” verdict were rejudged. Because, only the “Wrong Answer” verdict depends on the output files. Any other verdict depends on the input only. 3. Teams which got “Time Limit Exceeded” (TLE) after the rejudge were assumed potentially harmed because if they got the TLE during the contest they would have the opportunity to potentially optimize and improve their solution.

The entire judging team is disappointed that this mistake occurred. They acknowledge with full responsibility that the mistake is a grave one and apologizes to all the teams for their suffering.

Plagiarism in Submissions Two teams from University of Global Village were found to have plagiarised each other's submission for problem E. These two teams are: ● UGV_CodeBurners ● UGV-404 The incident was detected by the automatic plagiarism checker of Codemarshal. It was then manually verified by the Judges. Both teams were disqualified. Updated Ranklist Based on the issues mentioned above, the rank-list of the contest was modified slightly. We are attaching the previous and updated version of the rank-list for the top 20 teams, as major changes were limited to this range.

Previous Version Rank Name Institution Score Penalty 1 BUET Radiant University of Engineering and Technology 10 1194 2 BerlekampMassey Shahjalal University of Science and Technology 8 963 3 jU_zQxRdv 7 509 4 BUET: 3Q2 of Engineering and Technology 7 711 5 DU_NotStrongEnough 6 573 6 DU_FlareBlitz_4.0 University of Dhaka 6 630 7 IUT_Zeal Islamic University of Technology 6 774 8 SUST_Elevarse Shahjalal University of Science and Technology 6 866 9 JU_Glass_Half_Full Jahangirnagar University 6 1292 10 BUET_NerdHerd Bangladesh University of Engineering and Technology 5 344 11 IUT_Oporagoto Islamic University of Technology 5 460 12 BUET_cp_dropouts Bangladesh University of Engineering and Technology 5 460 13 AIUB_Captured American International University - Bangladesh 5 481 14 CUET_Sapphire Chittagong University of Engineering & Technology 5 484 15 DU_Untitled University of Dhaka 5 494 16 BUET Justice For Abrar Bangladesh University of Engineering and Technology 5 530 17 DU_Predator University of Dhaka 5 568 18 RUET_assert(0) University of Engineering & Technology 5 612 19 AUST_Onslaught Ahsanullah University of Science and Technology 5 685 20 BUET_Wildcard Bangladesh University of Engineering and Technology 5 719

Updated Version Possible Rank Name Institution Score Penalty Rank 1 BUET Radiant Bangladesh University of Engineering and Technology 10 1194 1 2 BerlekampMassey Shahjalal University of Science and Technology 8 963 2 3 jU_zQxRdv Jahangirnagar University 7 509 3 4 BUET: 3Q2 Bangladesh University of Engineering and Technology 7 711 4 5 DU_NotStrongEnough* University of Dhaka 7 719 5 6 DU_FlareBlitz_4.0 University of Dhaka 6 630 6 7 BUET_NerdHerd* Bangladesh University of Engineering and Technology 6 654 7 7 IUT_Zeal Islamic University of Technology 6 774 7 8 SUST_Elevarse Shahjalal University of Science and Technology 6 866 8 9 JU_Glass_Half_Full Jahangirnagar University 6 1292 9 11 IUT_Oporagoto Islamic University of Technology 5 460 11 12 BUET_cp_dropouts Bangladesh University of Engineering and Technology 5 460 12 13 AIUB_Captured American International University - Bangladesh 5 481 13 14 CUET_Sapphire Chittagong University of Engineering & Technology 5 484 14 15 DU_Untitled University of Dhaka 5 494 15 16 BUET Justice For Abrar** Bangladesh University of Engineering and Technology 5 530 9 17 DU_Predator University of Dhaka 5 568 17 18 RUET_assert(0)** Rajshahi University of Engineering & Technology 5 612 9 19 AUST_Onslaught Ahsanullah University of Science and Technology 5 685 19 20 BUET_Wildcard Bangladesh University of Engineering and Technology 5 719 20

* Teams which got accepted after the rejudge of problem C. ** Teams which were marked “Significantly Affected” for problem C. Selected Teams for ICPC Dhaka Regional 2020 Based on the discussion above and following the qualification criteria the selected teams are given below. The rule column corresponds with the rules in qualification criteria.

Name Institution Score Penalty Rule AUST_Onslaught Ahsanullah University of Science and Technology 5 685 3 AIUB_Captured American International University - Bangladesh 5 481 2 AIUB_Misfortuners American International University - Bangladesh 4 822 2 AIUB_Singularity American International University - Bangladesh 3 358 2 Fatman_and_LittleBoys Asian University of Bangladesh 2 344 3 BSMRSTU_Comfort_Zone_Cr Bangabandhu Science and Technology 3 549 2 ackers University BSMRSTU_Brain_Limit_Exce Bangabandhu Sheikh Mujibur Rahman Science and Technology 2 96 2 eded University TeamDeathMatch Bangladesh Army University of Engineering & Technology 2 274 3 BUBT_ModZero Bangladesh University of Business & Technology 3 396 2 BUBT_BugBag Bangladesh University of Business & Technology 2 109 2 BUET Radiant Bangladesh University of Engineering and Technology 10 1194 1 BUET: 3Q2 Bangladesh University of Engineering and Technology 7 711 1 BUET_NerdHerd Bangladesh University of Engineering and Technology 6 654 1 BUET_cp_dropouts Bangladesh University of Engineering and Technology 5 460 2 BUET Justice For Abrar Bangladesh University of Engineering and Technology 5 530 1* BUET_Wildcard Bangladesh University of Engineering and Technology 5 719 2 BUET_Dunder_Mifflin Bangladesh University of Engineering and Technology 5 741 2 BUET_Integers Bangladesh University of Engineering and Technology 5 1058 2* BUP_Aerolite 2.0 Bangladesh University of Professionals 4 583 3 BRUR_Crackdown , Rangpur 3 400 2 BRACU_Meadowlark BRAC University 4 580 3 BU_easily 2 117 3 CUET_Sapphire Chittagong University of Engineering & Technology 5 484 2 CUET_Tesseract Chittagong University of Engineering & Technology 4 621 2 CUET_BisherBashi Chittagong University of Engineering & Technology 3 274 2 CityU_Reverse_Case City University 2 191 3 CoU_Enigmatologist University 4 837 2 DIIT_extrano_programadores Daffodil Institute of Information Technology 2 326 3 DIU_Tr0jAnZ Daffodil International University 2 66 6 DIU_Thunders Daffodil International University 3 364 2 DIU_Tortuga Daffodil International University 3 480 2 DCC_Halcyon Dhaka City College 3 232 3 Bright_Coder Dhaka University of Engineering & Technology 2 71 3 EWU_We_Tried 3 481 2 EU_WA_TREE Eastern University of Bangladesh 2 326 3 GUB_Hoard_Warriors Green University of Bangladesh 2 323 3 HSTU_TREENITY Hajee Mohammad Danesh Science and Technology University 4 350 2 HABHIT_Twilight Haji Abul Hossain Institute of Technology 2 141 3 IST_neverGiveUp Institute of Science and Technology 3 473 3 IIUC_TEAM_MORALITY International Islamic University Chittagong 3 273 2 IUBAT_3Idi0ts_lasTTime International University of Business Agriculture and Technology 2 168 2 IU_JaniNa Islamic University 3 304 2 IU Spiral_Forge Islamic University 3 332 2 Name Institution Score Penalty Rule IUT_Zeal Islamic University of Technology 6 774 1 IUT_Oporagoto Islamic University of Technology 5 460 2 IUT Nidavellir Islamic University of Technology 4 791 2 IUT Monks Islamic University of Technology 3 329 2 JnU_Team_Shaky 4 550 3 jU_zQxRdv Jahangirnagar University 7 509 1 JU_Glass_Half_Full Jahangirnagar University 6 1292 1 JU_Amigos Jahangirnagar University 3 359 2 JU_ Viva-La-Vida Jahangirnagar University 3 387 2 JU_Team_Management Jahangirnagar University 3 410 2 JU_IncendIO Jahangirnagar University 3 419 2 JKKNIU_Team_Byatikrom Jatiya Kabi Kazi Nazrul Islam University 2 201 3 JUST_MAsK Jessore University of Science and Technology 2 161 2 KU_BackBenchers 2 67 3 KUET_Worst_Case Khulna University of Engineering & Technology 4 326 2 KUET_Sisyphus Khulna University of Engineering & Technology 4 447 2 KUET_ThunderBolt Khulna University of Engineering & Technology 4 510 2 KUET_LFS Khulna University of Engineering & Technology 4 547 2 LU_SchrodenBug 3 520 2 MBSTU_Durbeen Mawlana Bhashani Science & Technology University 4 450 2 MBSTU_Bekar_Jubok Mawlana Bhashani Science & Technology University 3 426 2 MU_Anirban Metropolitan University 2 45 2 MIST_NashInmate Military Institute of Science and Technology 2 61 6 mec_fighters Mymensingh Engineering College 2 310 3 NSTU_Cafeteria Noakhali Science and Technology University 3 296 2 NEUB_DivisionByZero Bangladesh 2 178 3 NSU_Stolichnaya 4 365 2 Return_0 Pabna University of Science and Technology 3 490 3 PSTU_WasThere Patuakhali Science and Technology University 5 792 2 PCIU_CODE_KNITTERS Port City International University 2 258 3 PUC Enigma 2 103 2 RUET_assert(0) Rajshahi University of Engineering & Technology 5 612 1* RUET_Trinity Rajshahi University of Engineering & Technology 3 301 2 RUET_Bug_Makers Rajshahi University of Engineering & Technology 3 303 2 RUET_WALovers Rajshahi University of Engineering & Technology 3 325 2* backBenchers_RMSTU Rangamati Science & Technology University 3 500 3 BerlekampMassey Shahjalal University of Science and Technology 8 963 1 SUST_Elevarse Shahjalal University of Science and Technology 6 866 1 SUST_Checkmate Shahjalal University of Science and Technology 5 751 2 SUST_Desvalido Shahjalal University of Science and Technology 5 765 2 SUST_Ambiguous Shahjalal University of Science and Technology 4 486 2 SUST_HOKOR Shahjalal University of Science and Technology 4 537 2 SEU_AggressiveCows Southeast University, Bangladesh 2 107 2 Stamford Invictus Stamford University Bangladesh 2 208 3 SUB_Prefix State University of Bangladesh 2 201 6 SEC_AlgoManiacs Engineering College 3 242 2 SEC_bug_lovers Sylhet Engineering College 3 311 2 SIU_Fighters Sylhet International University 2 314 3 Uap_Lumos The University of Asia Pacific 2 143 2 Name Institution Score Penalty Rule UIU_Dream United International University 3 563 2 Team_Robust University of 4 511 2 CU_Hypersonic 3 323 2 CU_AlphaLanterns University of Chittagong 2 66 2 DU_NotStrongEnough University of Dhaka 7 719 1 DU_FlareBlitz_4.0 University of Dhaka 6 630 1 DU_Untitled University of Dhaka 5 494 2 DU_Predator University of Dhaka 5 568 2 DU_Poltergeist University of Dhaka 4 369 2 DU_DarkHorsE_ University of Dhaka 4 698 6 UITS_MEEK_GEEK University of Information Technology & Sciences 2 114 3 ULAB_Disjoint_Skill_Union University of Liberal Arts Bangladesh 2 87 3 RU_Distilled_Coders 3 189 2 UU_Full_N_Final 2 362 3 VU_code_haters 2 221 3 WUB_Uronchondi World University of Bangladesh 2 161 3 * Based on the rejudge of problem C.

All Female Teams Name Institution Score Penalty Rule CUET_RAVENCLAW Chittagong University of Engineering & Technology 3 430 5 JU_O(try) Jahangirnagar University 3 464 5 RUET_RecycleBin Rajshahi University of Engineering & Technology 2 43 5

IOI Teams Name Institution Score Penalty Rule Siam, Mubasshir, Arman IOI 7 772 IOI Nafis, Jarif, Farhan IOI 4 538 IOI