Talk:ALGOL 68-primes
Source code
<lang algol68># primes.incl.a68: prime related operators, procedure etc. #
# returns a sieve of primes up to n # OP PRIMESIEVE = ( INT n )[]BOOL: BEGIN [ 1 : n ]BOOL prime; prime[ 1 ] := FALSE; prime[ 2 ] := TRUE; FOR i FROM 3 BY 2 TO UPB prime DO prime[ i ] := TRUE OD; FOR i FROM 4 BY 2 TO UPB prime DO prime[ i ] := FALSE OD; FOR i FROM 3 BY 2 TO ENTIER sqrt( UPB prime ) DO IF prime[ i ] THEN FOR s FROM i * i BY i + i TO UPB prime DO prime[ s ] := FALSE OD FI OD; prime END; # PRIMESIEVE #
- END primes.incl.a68 #
</lang>