31 lines
662 B
Plaintext
31 lines
662 B
Plaintext
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%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
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%%
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%% Sieve of eratosthenes to compute primes
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%% thom fruehwirth 920218-20, 980311
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%% christian holzbaur 980207 for Sicstus CHR
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%%
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%% ported to hProlog by Tom Schrijvers
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:- module(primes,[]).
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:- use_module(library(chr)).
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:- constraints candidate/1.
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:- constraints prime/1.
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candidate(1) <=> true.
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candidate(N) <=> primes:prime(N), N1 is N - 1, primes:candidate(N1).
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absorb @ prime(Y) \ prime(X) <=> 0 is X mod Y | true.
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time(N):-
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cputime(X),
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candidate(N),
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cputime( Now),
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Time is Now-X,
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write(N-Time), nl.
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cputime( Ts) :-
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statistics( runtime, [Tm,_]),
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Ts is Tm/1000.
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