Zhi-Qiang Lei
I have bungled the Prime Generator on SPOJ for many times. Although the program is faster and faster on my machine, but it keeps "time limited exceeded" on SPOJ (6 seconds limit). Now my approach is for every number in the range, check if it is prime by checking if can be divided by all the primes smaller than or equal its square root. For the numbers between 999900000 and 1000000000, it take 0.64 seconds on my laptop. Could anyone give me some hints to enhance it? Thanks.
There are some pretty good examples of fast prime generators here: http://www.haskell.org/haskellwiki/Prime_numbers although using them for SPOJ is a bit like cheating :) I learned a lot from that page though, so I advise giving it a good readover. -- Burton Samograd http://kruhft.dyndns.org