Christian Vest Hansen a écrit : > I think that count is O(n) for lists, no? >
Count is O(1) for lists but O(n) for a chain of conses. Clojure user=> (let [l (apply list (range 100000))] (time (dotimes [_ 1000000] (count l)))) "Elapsed time: 169.710116 msecs" nil user=> (let [l (apply list (range 400000))] (time (dotimes [_ 1000000] (count l)))) "Elapsed time: 167.664046 msecs" nil user=> (let [l (reduce #(cons %2 %1) nil (range 100000))] (time (dotimes [_ 100] (count l)))) "Elapsed time: 662.121862 msecs" nil user=> (let [l (reduce #(cons %2 %1) nil (range 1000000))] (time (dotimes [_ 100] (count l)))) "Elapsed time: 5316.110567 msecs" nil -- Professional: http://cgrand.net/ (fr) On Clojure: http://clj-me.blogspot.com/ (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 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 -~----------~----~----~----~------~----~------~--~---
