Copenhagen airport is located 8 kms south of Copenhagen city centre, and has flights to a large number of destinations. If you plan to go to Dublin to attend GECCO after ThRaSH, then you may consider reserving a cheap flight ticket with Norwegian.
Take a regional train or the Metro and get off at Nørreport Station. The City buses will take you straight from Nørreport Station to DIKU, get off at the University Park (Universitetsparken). You can use the bus line nos. 42, 43, 150S, 184 and 185. Approx. 40 minutes travelling time.
By taxi: Approx. DKK 250 and 20 minutes travelling time (depending on time of day).
By taxi: Approx. DKK 200 and 15 minutes travelling time (depending on time of day).
To get to Hotel Christian IV from Copenhagen Airport, use the Metro M2 and get off at Kongens Nytorv. Head north toward Store Kongensgade. After about 500 m, turn onto Dronningens Tværgade. After another 300 m, your destination will be on the left. Walking directions in Google Maps.
To get to Comfort Hotel Esplanaden from Copenhagen Airport, use the Metro M2 and get off at Kongens Nytorv. Then head east on Kongens Nytorv/O2 toward Holmens Kanal. Continue on Bredgade for about 1 km. Walking directions in Google Maps.
Alternatively, if you do not wish to walk from Kongens Nytorv, take Bus 1A from Kongens Nytorv/Magasin towards Hellerup st. (bus). Get off at Fredericiagade/Bredgade, which is the second stop after Kongens Nytorv. Then walk approx. 200 m north to Bredgade 78.