Welcome to OStack Knowledge Sharing Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
255 views
in Technique[技术] by (71.8m points)

c++ - How to check if given number is divisible of 15 in fastest way?

Division in processor takes much time, so I want to ask how to check in fastest way if number is divisible of some other number, in my case I need to check if number is divisible by 15.

Also I've been looking through web and found fun ways to check if number is divisible of some number, but I'm looking for fast option.

NOTE: as division takes much time I'm looking for answer without / and %.

See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Answer

0 votes
by (71.8m points)

Obligatory answer for other learners who might come looking for an answer.

if (number % n == 0)

In most cases, you can always do this, trusting the smart modern compilers.

This doesn't mean you get discouraged from learning fun ways though. Check out these links.

Fast divisibility tests (by 2,3,4,5,.., 16)?

Bit Twiddling Hacks


与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome to OStack Knowledge Sharing Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...