Depending on your requirements, the easiest way might be to simply list the entire ranges, for example all the IP's you given are RFC1918 (non routable) space, so you could get away with something like
mynetworks = 192.168.0.0/16, 10.0.0.0/8, 172.16.0.0/12
(If you are unfamiliar with it, the /XX at the end of each IP range tells how big the range is - /24 is a class C)
If you only have IP addresses in those ranges, ie you could have a host as 192.168.1.3 another as 192.168.20.44 and both would be covered as they are part of the bigger non-routed block. (Just don't do this with IP addresses which are routable).
Another way to make life easier might be to use a hash table, mysql table or regex list (as you might do for other options) to put this information into a separately parsed file. See DATABASE_README.html#types for a list of lookup table types