Difference between revisions of "Talk:Prime numbers"
(An interesting thought) |
m |
||
| Line 8: | Line 8: | ||
[[User:MathematicalOrchid|MathematicalOrchid]] 16:41, 5 February 2007 (UTC) |
[[User:MathematicalOrchid|MathematicalOrchid]] 16:41, 5 February 2007 (UTC) |
||
| + | |||
| + | a composite can indeed have factors greater than its square root, and indeed most do. what you mean is that a composite will definitely have at least one factor smaller-equal than its square root. |
||
| + | |||
| + | why not use <hask>(\x -> n > x*x)</hask> --[[User:JohannesAhlmann|Johannes Ahlmann]] 21:18, 5 February 2007 (UTC) |
||
Revision as of 21:18, 5 February 2007
Here's an interesting question: will the program go faster if we replace all those (n >) expressions with (\x -> floor (sqrt n) > x)?
On one hand, a composite integer cannot possess a factor greater than its square root.
On the other hand, since the list we're looking through contains all possible prime numbers, we are guaranteed to find a factor or an exact match eventually, so do we need the takeWhile at all?
Throwing this over to somebody with a bigger brain than me...
MathematicalOrchid 16:41, 5 February 2007 (UTC)
a composite can indeed have factors greater than its square root, and indeed most do. what you mean is that a composite will definitely have at least one factor smaller-equal than its square root.
why not use (\x -> n > x*x) --Johannes Ahlmann 21:18, 5 February 2007 (UTC)