wondering about other people's code runtimes

[rich_correia]

Hi

I just started solving a couple problems today. As I was wondering about the site I noticed that, while my runtime to problem 100, (the 3n+1 thing), was something relatively lengthy other people had runtimes of 0 and 0.001, something like that, very fast.
Do they write parts of the code in assembler? What gives?

Rich

[rio]

pre-calculate teq, and fast i/o.

[rich_correia]

sorry dude, what does precalculated teq mean?

[Debashis Maitra]

precalculated teq means precalculated output

[Roby]

AND print the formatted output directly

But I a little bit curious about the fast I/O... I always use gets to make my solution faster... but it was "less" faster than I thought... So, can someone give me an example how to make fast I/O parser? Thanks.

[Vexorian]

In a less esoteric way of doing things, 100 has a fast solution in which you keep an array as a table for solutions you got already. For example f(15) requires your to solve f(46) so if you later go through f(46) you don't have to calculate f(46) again since the program 'remembers' the solution for it.

A good thing to do is to solve http://acm.uva.es/problemset/v3/371.html after solving 100 and notice the differences.