if anyone is interested, i used reduces instead of reductions.
2012/12/11 Dennis Haupt <d.haup...@gmail.com> > i just saw my error.... :/ > > > Am 11.12.2012 22:22, schrieb Ben Wolfson: > > nth is called in doing the destructuring for the argument lists in > > your fns defined in try-find-sequence. > > > > On Tue, Dec 11, 2012 at 1:20 PM, Dennis Haupt <d.haup...@gmail.com> > wrote: > >> i am trying to solve euler problem 125. when i tested this code: > >> > >> (ns euler.Problem125) > >> > >> (defn is-palindrome [n] > >> (let [s (str n)] > >> (= (seq s) (reverse s)))) > >> > >> (defn to-check [] > >> (filter is-palindrome (range 1 1000))) > >> > >> (defn square-root [n] > >> (Math/sqrt n)) > >> > >> (defn squared [n] > >> (* n n)) > >> > >> (defn try-find-sequence [n] > >> (loop [start-at (int (square-root n))] > >> (let [combinator (fn [[sum smallest] element] [(+ sum element) (dec > >> element)]) > >> reduced (reduce combinator [0 start-at] (range start-at 0 -1)) > >> pred (fn [[sum smallest]] (> sum n)) > >> until-match-or-overflow (take-while pred reduced) > >> solution-or-not (last until-match-or-overflow)] > >> (cond > >> (= (first solution-or-not) n) nil > >> (= (first solution-or-not) n) (second solution-or-not) > >> :else (recur (dec start-at)))))) > >> (println (try-find-sequence 595)) > >> > >> i get: > >> Exception in thread "main" java.lang.UnsupportedOperationException: nth > >> not supported on this type: Long > >> at clojure.lang.RT.nthFrom(RT.java:846) > >> at clojure.lang.RT.nth(RT.java:796) > >> at > euler.Problem125$try_find_sequence$pred__16.invoke(Problem125.clj:20) > >> at clojure.core$take_while$fn__4116.invoke(core.clj:2512) > >> > >> but why? i don't call nth on anything! > >> > >> -- > >> 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 > > > > > > > > > -- > > -- 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
