24 lines
678 B
Erlang
24 lines
678 B
Erlang
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% Erlang version of a Prime Number Finder
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% haplo@mindstab.net
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-module(primes).
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-author('haplo@mindstab.net').
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-export([primes/1]).
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check(I, Cnt, Max) when I < Max, (Cnt rem I) == 0 -> 0;
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check(I, Cnt, Max) when I < Max -> check(I+2, Cnt, Max);
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check(I, Cnt, Max) -> 1.
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primes([Max]) -> primes(3, list_to_integer(atom_to_list(Max)), 2, 4);
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primes(Max) -> primes(3, Max, 2, 4).
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primes(Cnt, Max, Sq, Sqm) when Cnt < Max, Cnt >= Sqm ->
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primes(Cnt, Max, Sq+1, (Sq+1)*(Sq+1));
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primes(Cnt, Max, Sq, Sqm) when Cnt < Max ->
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case check(3, Cnt, Sq) of
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0 -> 0;
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C -> io:format("~p\n", [Cnt])
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end,
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primes(Cnt+2, Max, Sq, Sqm)
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;
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primes(Cnt, Max, Sq, Sqm) -> init:stop().
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