how to reduce time limit exceed?

general
,
1

when i submit a problem sometimes it shows time limit exceeds .
so how can i reduce my time limit and how can i make it efficient

2

Use efficient algorithms (depending on the constraints).Or if there are large I/O files in the program use fast I/O methods.For more idea about faster I/O methods refer the problem INTEST :

link-http://www.codechef.com/problems/INTEST

Hope that this helps :).