Dont Know wrote: > The solution I know, needs O(n) space. Take a circular queue of size > n. Read a line at a time from the file and insert it into the queue. > If the queue is full remove the first line and insert the newly read > line. Repeat this process untill EOF is encountered. When we reach > end of the file the queue will contain the last n lines of the file.
The problem with this is that it could involve a LOT of work (and time), that isn't necessary. OP stated that the file could be a huge one. When you open a file, you have a file pointer, already. Just move the file pointer to the end of the file, (just one command), and begin backing up from that point. When you've encountered n number of CR/LF, char's, you're ready to swap directions with the file pointer, and just read the data like you normally would, until you reach EOF. If the OS and / or your language offers a simple way to do a task, it's almost always best to use it. Adak --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Algorithm Geeks" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/algogeeks -~----------~----~----~----~------~----~------~--~---
