Lab46 Wiki

User Tools

Site Tools

You are here: start » notes » comporg » projects » pnc0
notes:comporg:projects:pnc0

Differences

This shows you the differences between two versions of the page.

Link to this comparison view

Both sides previous revisionPrevious revision
Next revision		Previous revision
notes:comporg:projects:pnc0 [2018/01/21 01:54] – [Program Specifications] ahought2notes:comporg:projects:pnc0 [2018/01/22 13:51] (current) – [Program Output Format] bstrong2
Line 105: Line 105:
  
 **Square root trick** - You can use the <math.h> include file with **sqrt()** function or approximate the square root process using logic (this could potentially save runtime because you are not checking as many things as the sqrt function would check through).  The premisis is that you only need to check factors of a number up until the Square root of that number.  For example the square root of 25 is 5.  This tells us that you only need to check factors 2 through 5 to find if this number is a prime or not. **Square root trick** - You can use the <math.h> include file with **sqrt()** function or approximate the square root process using logic (this could potentially save runtime because you are not checking as many things as the sqrt function would check through).  The premisis is that you only need to check factors of a number up until the Square root of that number.  For example the square root of 25 is 5.  This tells us that you only need to check factors 2 through 5 to find if this number is a prime or not.
 +<code>
 +#include <math.h>
 +</code>
 +
 +**sqrt()-less square root approximation (a)-** This is optional, you would do this instead of the sqrt() function. (If you've taken discrete then you know how to do it, if you haven't taken discrete and are looking for moar then this is an option.) The sqrt function in the math library does an exact calculation of a square root. Since we are only dealing with whole numbers for our prime project it is possible to create your own logic to approximate the square root. Since the sqrt function will run for every number that is being checked you are looking at quite a performance increase.
 ---- ----
 **primereg.c** - baseline program (Brute force, no break)\\ \\ **primereg.c** - baseline program (Brute force, no break)\\ \\
Line 130: Line 135:
  
 -**Put all c files in gcc directory from pnc0 grabit** \\ -**Put all c files in gcc directory from pnc0 grabit** \\
--Numbers go to stderr, time goes to stdout \\+-Numbers go to stderr, **time goes to stdout** \\
  
 =====Testing===== =====Testing=====
notes/comporg/projects/pnc0.1516499687.txt.gz · Last modified: 2018/01/21 01:54 by ahought2

Page Tools

Except where otherwise noted, content on this wiki is licensed under the following license: CC Attribution-Share Alike 4.0 International
CC Attribution-Share Alike 4.0 International Donate Powered by PHP Valid HTML5 Valid CSS Driven by DokuWiki