Digital root/Multiplicative digital root: Difference between revisions

<lang rexx>/*REXX pgmprogram finds the persistence and multiplicative digital root of some #'snumbers.*/

numeric digits 100 /*increase the number of digits.decimal digits*/

parse arg x /*getobtain someoptional numbersarguments from the C.L. CL*/

if x='' | x="," then x=123321 7739 893 899998 /*useNot defaultsspecified? if noneThen specifieduse the default.*/

say center('number', 8) ' persistence multiplicative digital root'

say copies('─' , 8) ' ─────────── ───────────────────────────'

/* [↑] the title and separator. */

do j=1 for words(x); n=word(x, j) /*process each number in the X list.*/

parse value mdr MDR(n) with mp mdr /*obtain the persistence and the MDR. */

say right(n,8) center(mp,13) center(mdr,30) /*display #a number, mp persistence, mdr MDR.*/

end /*j*/ /* [↑] show MP and& MDR for each #number. */

say; target=5

do m=k=0 untilfor 10; hits=0; _=target /*findshow targetnumbers #sthat withhave an MDR of K. */

ifdo word(mdr(m),2)\==k thenuntil hits==target iterate /*isfind thetarget MDRnumbers what'swith an MDR wanted?of K.*/

hits=hits+1; if _=spaceword(_ MDR(m'),' 2)\==k then iterate /*yes,is wethis gotthe MDR that's wanted? a hit, add to list.*/

end /*m*/ hits=hits + 1; _=space(_ m',') /*yes, [↑]we builtgot a listhit, of MDRsadd =to kthe list. */

say " "k':end /*m*/ ['strip(_,,',')"]" /*display the[↑] Kbuilt a (mdr)list andof listMDRs that = K. */

endsay " /*"k*/': ['strip(_, , ',')"]" /*display the K /* [↑] (MDR) done withand the K mdr list. */

exit end /*k*/ /*stick a[↑] fork indone it,with we'rethe done K MDR list. */

MDR: procedure; parse do p=1 untilarg y; y<10=abs(y) /*get the number and determine /*findthe multiplicative digRoot (Y)MDR.*/

parse var y 1 r 2; do kp=21 to length(y); r=r*substr( until y,k,1)<10; end; parse var y= r 2

end /*p*/ do k=2 to length(y); r=r /*wash substr(y, rinsek, repeat ··· */1)

return p r end /*return the persistence and MDR.k*/</lang>