I should re-test before post. This version of the main loop actually
terminates (for smaller numbers), but will still blow up:
(loop [ p (first perms) r (rest perms) s 0 c 0 ]
(if (> c 8)
s
(if (every? #(%1 p) guards)
(do
(println p)
(recur (first r) (rest r) (+ s (seq-to-val p)) (inc c)))
(recur (first r) (rest r) s c))))
Regards,
Dirk
On Mon, Mar 9, 2009 at 4:55 PM, Dirk Vleugels <[email protected]> wrote:
> Hi,
>
> $ time clojure euler43.clj
> (1 4 0 6 3 5 7 2 8 9)
> (1 4 3 0 9 5 2 8 6 7)
> (1 4 6 0 3 5 7 2 8 9)
> java.lang.OutOfMemoryError: Java heap space
> Dumping heap to java_pid7476.hprof ...
>
> The hprof file is 330mb in size, i can't read it with jhat (even if i
> give it 1.5G ....).
>
> I assume perms is the problem, but i dont know how to write this in a
> more memory efficient way - I'm not looking for a more efficient
> algorithm though....
>
> Thanx for any hint,
> Dirk
>
> (use 'clojure.contrib.combinatorics)
>
> (def perms (permutations (range 10)))
>
> (defn seq-to-val [ s ]
> (reduce #(+ (* %1 10) %2) s))
>
> (defn extract [ s i ]
> (conj [] (nth s i) (nth s (inc i)) (nth s (inc (inc i)))))
>
> (defn f24 [ s ]
> (= (mod (seq-to-val (extract s 1)) 2) 0))
>
> (defn f35 [ s ]
> (= (mod (seq-to-val (extract s 2)) 3) 0))
>
> (defn f46 [ s ]
> (= (mod (seq-to-val (extract s 3)) 5) 0))
>
> (defn f57 [ s ]
> (= (mod (seq-to-val (extract s 4)) 7) 0))
>
> (defn f68 [ s ]
> (= (mod (seq-to-val (extract s 5)) 11) 0))
>
> (defn f79 [ s ]
> (= (mod (seq-to-val (extract s 6)) 13) 0))
>
> (defn f810 [ s ]
> (= (mod (seq-to-val (extract s 7)) 17) 0))
>
> (def guards [ f24 f35 f46 f57 f68 f79 f810 ])
>
> (loop [ p (first perms) r (rest perms) sum 0 count 0 ]
> (when (= count 10)
> sum)
> (if (every? #(%1 p) guards)
> (do
> (println p)
> (recur (first r) (rest r) (+ sum (seq-to-val p)) (inc count)))
> (recur (first r) (rest r) sum (inc count))))
>
--
Dirk Vleugels
2scale GmbH
--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups
"Clojure" group.
To post to this group, send email to [email protected]
To unsubscribe from this group, send email to
[email protected]
For more options, visit this group at
http://groups.google.com/group/clojure?hl=en
-~----------~----~----~----~------~----~------~--~---
