PC2021: Intermediate results, Problem 4, week 7

By 16th May 2021, there are 1050 registered participants from 71 countries (the list of countries is given below). During the first seven weeks, 40 solutions were submitted, out of which 19 had at least one correct part, a or b, see the 0-th hint.

Correct solutions for the part a were submitted by:

First NameSurnameCountrySchool/Universitydatetime
HuiyuanWangChinaUniversity of Cambridge28/03/202121:28
ZheningLiCanadaSir John A. Macdonald Secondary School29/03/202104:23
LotusChenChinaNo.2 High School Shijiazhuang30/03/202115:56
AntoniaGhitaRomaniaInternational Computer High School of Bucharest01/04/202114:29
OliwierUrbańskiPolandLiceum Ogólnokształcące nr 7 w Poznaniu03/04/202111:52
JoshuaTeoSingaporeNUS High School04/04/202112:27
NikitaSemeninRussiaMoscow Institute of Physics and Technology05/04/202115:55
M. SubhiAbo RdanSyriaKnowledge private schools08/04/202108:56
Caio AugustoSiqueira da SilvaBrazilColégio Objetivo Integrado13/04/202102:16
Vlad-ȘtefanOrosRomania“Grigore Moisil” Informatics High School13/04/202116:00
QianLinChinaUniversity of Oxford01/05/202114:47
YanjunZhouUnited KingdomUniversity of Oxford02/05/202123:29
Ameya VikramaSinghIndiaFIITJEE Junior College03/05/202110:58
DanielSchillerGermanyRuprecht-Karls-Universität Heidelberg08/05/202121:44
VukHipSerbiaMathematical grammar school11/05/202108:56
Sebastián AndrésArévalo AguirreEl SalvadorInstituto Emiliani16/05/202106:38
AlexandarRoussevBulgariaFirst Language School16/05/202111:21

Correct solutions for the part b were submitted by:

First NameSurnameCountrySchool/Universitydatetime
ZheningLiCanadaSir John A. Macdonald Secondary School29/03/202104:23
NikitaSemeninRussiaMoscow Institute of Physics and Technology29/03/202109:07
OliwierUrbańskiPolandLiceum Ogólnokształcące nr 7 w Poznaniu29/03/202112:18
TevžLotričSloveniaUniversity of Oxford29/03/202122:28
HuiyuanWangChinaUniversity of Cambridge05/04/202100:23
Vlad-ȘtefanOrosRomania“Grigore Moisil” Informatics High School13/04/202116:00
JaroslavHermanCzechiaCharles University28/04/202122:04
YanjunZhouUnited KingdomUniversity of Oxford02/05/202123:29
QianLinChinaUniversity of Oxford08/05/202116:02

Participating countries: Algeria, Azerbaijan, Australia, Bangladesh, Belarus, Belgium, Bosnia and Herzegovina, Bolivia, Brazil, Bulgaria, Cambodia, Canada, China, Croatia, Czechia, Egypt, El Salvador, Estonia, Finland, Georgia, Germany, Greece, Hungary, India, Indonesia, Iran, Israel, Italy, Japan, Kazakhstan, Kenya, Korea, Kyrgyzstan, Latvia, Lebanon, Lithuania, Macedonia, Malaysia, Mexico, Moldova, Mongolia, Nepal, Nigeria, North Macedonia, Pakistan, Peru, Philippines, Poland, Romania, Russia, Saudi Arabia, Serbia, Singapore, Slovakia, Slovenia, South Africa, South Korea, Spain, Sri Lanka, Sweden, Switzerland, Syria, Taiwan, Thailand, Turkey, Turkmenistan, United Arab Emirates, United Kingdom, United States, Uzbekistan, Vietnam.