Short-term residence
If you are visiting the Czech Republic for only a few days or weeks, there is a wide range of hotels, pensions, and hostels available, and reservations can be made, for example, on Booking.com.
Options for the dormitories of Charles University can be found here: Dormitories in Hradec Králové - Dormitories and Refectories.
Another possibility of accomodation in Hradec Králové: House Campus.
Long-term residence
Options for the dormitories of Charles University can be found here: Dormitories in Hradec Králové - Dormitories and Refectories.