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    <p>You can use <a href="http://www.erlang.org/doc/man/timer.html#tc-1" rel="nofollow">timer</a> module to check speed of execution:</p> <pre><code>{Time, Value} = timer:tc(queen, queen, [N]) </code></pre> <p>Or you can transform you code to escript:</p> <pre><code>#!/usr/bin/env escript -mode(native). %% to fun faster main([NStr]) -&gt; N = list_to_integer(NStr), IJ = [{I, J} || I &lt;- lists:seq(1, N), J &lt;- lists:seq(1, N)], lists:foreach(fun({I, J}) -&gt; put_data(I, J, true) end, IJ), solve(N, 1, [], 0). solve(N, J, Board, Count) when N &lt; J -&gt; print(N, Board), Count + 1; solve(N, J, Board, Count) -&gt; F = fun(I, Cnt) -&gt; case get_data(I, J) of true -&gt; put_data(I, J, false), Cnt2 = solve(N, J+1, [I|Board], Cnt), put_data(I, J, true), Cnt2; false -&gt; Cnt end end, lists:foldl(F, Count, lists:seq(1, N)). put_data(I, J, Bool) -&gt; put({row, I }, Bool), put({add, I+J}, Bool), put({sub, I-J}, Bool). get_data(I, J) -&gt; get({row, I}) andalso get({add, I+J}) andalso get({sub, I-J}). print(N, Board) -&gt; Frame = "+-" ++ string:copies("--", N) ++ "+", io:format("~s~n", [Frame]), lists:foreach(fun(I) -&gt; print_line(N, I) end, Board), io:format("~s~n", [Frame]). print_line(N, I) -&gt; F = fun(X, S) when X == I -&gt; "Q " ++ S; (_, S) -&gt; ". " ++ S end, Line = lists:foldl(F, "", lists:seq(1, N)), io:format("| ~s|~n", [Line]). </code></pre> <p>and make it executable from linux shell:</p> <pre><code>chmod +x queue </code></pre> <p>And then run it from linux shell with command <code>./queue</code> or <code>time ./queue</code></p>
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    1. POHow to compile and run this code without using erlang shell
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    1. POHow to compile and run this code without using erlang shell
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    1. COOf course the measured time then includes the time to start erlang and compile the code, as well as running the actual code.
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    2. COThanks for your reply. I prefer the second method using escript. But I cannot run it in native mode because of the following error: Warning: this system is not configured for native-code compilation. escript: exception error: no function clause matching test__escript__1383__893414__479613:main([]) (./test, line 5) in function escript:run/2 (escript.erl, line 747) in call from escript:start/1 (escript.erl, line 277) in call from init:start_it/1 in call from init:start_em/1 How can I configure my system to run it in native mode?
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    3. COProbably you should create new question.
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