Abundant, deficient and perfect number classifications: Difference between revisions

→‎{{header|REXX}}: added the REXX language. -- ~~~~
(scheme implementation)
(→‎{{header|REXX}}: added the REXX language. -- ~~~~)
Line 524:
15043 deficient numbers
4 perfect numbers
</pre>
 
=={{header|REXX}}==
<lang rexx>/*REXX pgm counts the # of abundant/deficient/perfect numbers in a range*/
parse arg low high . /*get optional arguments*/
high=word(high low 20000,1); low=word(low 1,1) /*get the LOW and HIGH. */
say center('integers from ' low " to " high, 45, "═")
!.=0 /*set all types of sums to zero. */
do j=low to high; $=sigma(j) /*find the sigma for an int range*/
if $<j then !.d=!.d+1 /*it's a deficient number*/
else if $>j then !.a=!.a+1 /* " " abundant " */
else !.p=!.p+1 /* " " perfect " */
end /*j*/
 
say ' the number of perfect numbers: ' right(!.p, length(high))
say ' the number of abundant numbers: ' right(!.a, length(high))
say ' the number of deficient numbers: ' right(!.d, length(high))
exit /*stick a fork in it, we're done.*/
/*──────────────────────────────────SIGMA subroutine────────────────────*/
sigma: procedure; parse arg x; if x<2 then return 0; odd=x//2
s=1 /* [↓] use only EVEN|ODD integers*/
do j=2+odd by 1+odd while j*j<x /*divide by all integers up to √x*/
if x//j==0 then s=s+j+ x%j /*add the two divisors to the sum*/
end /*j*/ /* [↑] % is REXX integer divide*/
/* [↓] adjust for square. _ */
if j*j==x then s=s+j /*Was X a square? If so, add √x.*/
return s /*return the sum of the divisors.*/</lang>
'''output''' &nbsp; when using the default inputs:
<pre>
═════════integers from 1 to 20000═════════
the number of perfect numbers: 4
the number of abundant numbers: 4953
the number of deficient numbers: 15043
</pre>