you can define a function to filter the result
like
(defn answer? [x] (filter #(every? integer? %) x))
and then just call it by doing
user=> (map #(answer? %) (trips (range 1 7)))
(() () ([3 4 5]) () ())
On Wed, Mar 10, 2010 at 1:20 PM, Glen Rubin <rubing...@gmail.com> wrote:
> I am working on the following problem:
>
> Find the only Pythagorean triplet, {a, b, c}, for which a + b + c =
> 1000
>
> My strategy is to produce a series of triplets of a^2 + b^2 and then
> filter out the ones where the c^2 is a perfect square, in order to
> determine Pythagorean triplets.
>
> I wrote a function to produce triplets that takes a range as input:
>
>
> (use '[clojure.contrib.math :only (sqrt)])
>
> (defn trips [coll]
> (loop [a (first coll) b (rest coll) trip []]
> (cond (seq b)
> (recur (first b) (rest b) (conj trip (map #(vector a % (sqrt (+ (*
> a a) (* % %)))) b)))
> true trip)))
>
>
> ,so if I want to see all triplets over the range of 1-7, I just do:
>
> (trips (range 1 7)), which yields the following;
>
> [([1 2 2.23606797749979] [1 3 3.1622776601683795] [1 4
> 4.123105625617661] [1 5 5.0990195135927845] [1 6 6.082762530298219])
> ([2 3 3.605551275463989] [2 4 4.47213595499958] [2 5
> 5.385164807134504] [2 6 6.324555320336759]) ([3 4 5] [3 5
> 5.830951894845301] [3 6 6.708203932499369]) ([4 5 6.4031242374328485]
> [4 6 7.211102550927978]) ([5 6 7.810249675906654])]
>
> Obviously the only Pythagorean triplet burried in there is 3, 4, 5.
>
> Now, I can easily test a single vector for integers as follows:
>
> (map integer? [5 6 7])
>
> However, the output of my trips function yields multiple collections
> of vectors inside of a larger vector. I am completely befuddled as to
> how to process this behemoth.
>
> I guess I need to use some functions for merging collections?
>
> Any help apprectiated. thanks!!
>
> --
> You received this message because you are subscribed to the Google
> Groups "Clojure" group.
> To post to this group, send email to clojure@googlegroups.com
> Note that posts from new members are moderated - please be patient with your
> first post.
> To unsubscribe from this group, send email to
> clojure+unsubscr...@googlegroups.com
> For more options, visit this group at
> http://groups.google.com/group/clojure?hl=en
--
Omnem crede diem tibi diluxisse supremum.
--
You received this message because you are subscribed to the Google
Groups "Clojure" group.
To post to this group, send email to clojure@googlegroups.com
Note that posts from new members are moderated - please be patient with your
first post.
To unsubscribe from this group, send email to
clojure+unsubscr...@googlegroups.com
For more options, visit this group at
http://groups.google.com/group/clojure?hl=en
