ALGOL 68/prelude
< ALGOL 68
The following summarises the useful and various ALGOL 68 prelude templates. These are used in several ALGOL 68 code samples.
pow_mod.a68
Used in: Miller-Rabin test and Multiplicative order. Could be used in Trial factoring of a Mersenne number.
COMMENT This routine is used in more than one place, and is essentially a template that can by used for many different types, eg INT, LONG INT... USAGE MODE POWMODSTRUCT = INT, LONG INT, COMPL, FRAC, MODULAS, MATRIX etc PR READ "prelude/pow_mod.a68" PR END COMMENT
PROC pow mod = (POWMODSTRUCT b,in e, mod)POWMODSTRUCT: ( POWMODSTRUCT sq := b, e := in e; POWMODSTRUCT out:= IF ODD e THEN b ELSE 1 FI; e:=e OVER 2; WHILE e /= 0 DO sq := sq * sq %* mod; IF ODD e THEN out := out * sq %* mod FI ; e:=e OVER 2 OD; out )
sort.a68
Used in: Multiplicative order and Sort most popular programming languages.
COMMENT This routine is used in more then one place, and is essentially a template that can by used for many different types, eg INT, LONG INT... USAGE MODE SORTSTRUCT = INT, LONG INT, STRUCT(STRING name, addr) etc OP < = (SORTSTRUCT a,b)BOOL: ~; PR READ "prelude/sort.a68" PR; [3]SORTSTRUCT list := (a,b,c); print((in place shell sort(list), new line)) END COMMENT
PROC in place shell sort = (REF FLEX []SORTSTRUCT seq)REF[]SORTSTRUCT:( INT inc := ( UPB seq + LWB seq + 1 ) OVER 2; WHILE inc NE 0 DO FOR index FROM LWB seq TO UPB seq DO INT i := index; SORTSTRUCT el = seq[i]; WHILE ( i - LWB seq >= inc | NOT(seq[i - inc] < el) | FALSE ) DO seq[i] := seq[i - inc]; i -:= inc OD; seq[i] := el OD; inc := IF inc = 2 THEN 1 ELSE ENTIER(inc * 5 / 11) FI OD; seq );
PROC in place shell sort reverse = (REF FLEX []SORTSTRUCT seq)REF[]SORTSTRUCT:( INT inc := ( UPB seq + LWB seq + 1 ) OVER 2; WHILE inc NE 0 DO FOR index FROM LWB seq TO UPB seq DO INT i := index; SORTSTRUCT el = seq[i]; WHILE ( i - LWB seq >= inc | seq[i - inc] < el | FALSE ) DO seq[i] := seq[i - inc]; i -:= inc OD; seq[i] := el OD; inc := IF inc = 2 THEN 1 ELSE ENTIER(inc * 5 / 11) FI OD; seq ); SKIP