Revision as of 22:16, 5 July 2021 (view source) rosettacode>Gerard Schildberger m (→‎{{header\|REXX}}: changed whitespace and comments, added a foot separator for the output.) ← Older edit		Revision as of 16:06, 29 August 2021 (view source) Tigerofdarkness (talk \| contribs) (→‎{{header\|ALGOL 68}}: Use ALGOL 68-primes) Newer edit →
Line 13: =={{header\|ALGOL 68}}== {{libheader\|ALGOL 68-primes}} <lang algol68>BEGIN # Show some values of pi(n) - the number of priems <= n # ~~# reurns a sieve of primes up to n #~~ ~~PROC prime sieve = ( INT n )[]BOOL:~~ ~~BEGIN~~ ~~[ 1 : n ]BOOL p;~~ ~~p[ 1 ] := FALSE; p[ 2 ] := TRUE;~~ ~~FOR i FROM 3 BY 2 TO n DO p[ i ] := TRUE OD;~~ ~~FOR i FROM 4 BY 2 TO n DO p[ i ] := FALSE OD;~~ ~~FOR i FROM 3 BY 2 TO ENTIER sqrt( n ) DO~~ ~~IF p[ i ] THEN FOR s FROM i * i BY i + i TO n DO p[ s ] := FALSE OD FI~~ ~~OD;~~ p ~~END # prime sieve # ;~~ # show pi(n) for n up to 21 # INT max ~~number~~prime = 100; # guess of how large the primes we need are # INT max pi = 21; PR read "primes.incl.a68" PR []BOOL prime = ~~prime sieve(~~PRIMESIEVE max ~~number )~~prime; INT pi := 0; FOR i TO ~~max~~UPB ~~number~~prime WHILE IF prime[ i ] THEN pi +:= 1 FI; pi <= max pi Line 50 ⟶ 40: 20 20 21 21 21 21 21 21 </pre> =={{header\|Arturo}}==

Piprimes (view source)