93 lines
5.8 KiB
Rexx
93 lines
5.8 KiB
Rexx
/*REXX pgm implements a reasonably complete rational arithmetic (fract.)*/
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L=length(2**19-1) /*saves time by checking even #s.*/
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do j=2 to 2**19-1 by 2 /*ignore unity (can't be perfect)*/
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$=divisors(j); s=0; @= /*get divisors, zero sum, null @.*/
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do k=2 to words($) /*ignore unity.*/
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r='1/'word($,k); @=@ r; s=fractFun(r,,s)
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end /*k*/
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if s\==1 then iterate
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say 'perfect number:' right(j,L) ' fractions:' @
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end /*j*/
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exit /*stick a fork in it, we're done.*/
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/*──────────────────────────────────FRACTDIV subroutine─────────────────*/
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fractDiv: procedure; parse arg x; x=space(x,0); f='FractDiv'
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parse var x n '/' d; d=p(d 1)
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if d=0 then call err 'division by zero:' x
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if \isNum(n) then call err 'a not numeric numerator:' x
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if \isNum(d) then call err 'a not numeric denominator:' x
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return n/d
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/*──────────────────────────────────FRACTFUN subroutine─────────────────*/
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fractFun: procedure; parse arg z.1,,z.2 1 zz.2,f; arg ,op; op=p(op '+')
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f='FractFun'; do j=1 for 2; z.j=translate(z.j,'/',"_"); end /*j*/
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if abbrev('ADD' ,op) then op='+'
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if abbrev('DIVIDE' ,op) then op='/'
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if abbrev('INTDIVIDE' ,op,4) then op='÷'
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if abbrev('MODULO' ,op,3) | abbrev('MODULUS' ,op,3) then op='//'
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if abbrev('MULTIPLY' ,op) then op='*'
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if abbrev('POWER' ,op) then op='^'
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if abbrev('SUBTRACT' ,op) then op='-'
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if z.1=='' then z.1=(op\=="+" & op\=='-') /*unary +,-*/
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if z.2=='' then z.2=(op\=="+" & op\=='-')
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z_=z.2
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do j=1 for 2 /*verification of both fractions.*/
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if pos('/',z.j)==0 then z.j=z.j"/1"; parse var z.j n.j '/' d.j
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if \isNum(n.j) then call err 'a not numeric numerator:' n.j
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if \isNum(d.j) then call err 'a not numeric denominator:' d.j
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n.j=n.j/1; d.j=d.j/1
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do while \isInt(n.j); n.j=(n.j*10)/1; d.j=(d.j*10)/1
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end /*while*/ /* [↑] normalize both numbers. */
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if d.j=0 then call err 'a denominator of zero:' d.j
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g=gcd(n.j,d.j); if g=0 then iterate; n.j=n.j/g; d.j=d.j/g
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end /*j*/
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select
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when op=='**' | op=='↑' |,
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op=='^' then do; if \isInt(z_) then call err 'a not integer power:' z_
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t=1; u=1; do j=1 for abs(z_); t=t*n.1; u=u*d.1
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end /*j*/
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if z_<0 then parse value t u with u t
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end
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when op=='/' then do; if n.2=0 then call err 'a zero divisor:' zz.2
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t=n.1*d.2; u=n.2*d.1
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end
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when op=='÷' then do; if n.2=0 then call err 'a zero divisor:' zz.2
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t=trunc(fractDiv(n.1 '/' d.1)); u=1
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end /* [↑] integer division. */
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when op=='//' then do; if n.2=0 then call err 'a zero divisor:' zz.2
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_=trunc(fractDiv(n.1 '/' d.1)); t=_-trunc(_)*d.1; u=1
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end /* [↑] modulus division. */
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when op=='+' |,
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op=='-' then do; l=lcm(d.1 d.2); do j=1 for 2; n.j=l*n.j/d.j; d.j=l
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end /*j*/
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if op=='-' then n.2=-n.2; t=n.1+n.2; u=l
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end
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when op=='ABS' then do; t=abs(n.1); u=abs(d.1); end
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when op=='*' then do; t=n.1*n.2; u=d.1*d.2; end
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when op=='EQ' |,
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op=='=' then return fractDiv(n.1 '/' d.1) = fractDiv(n.2 '/' d.2)
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when op=='NE' | op=='\=' | op=='╪' |,
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op=='¬=' then return fractDiv(n.1 '/' d.1) \= fractDiv(n.2 '/' d.2)
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when op=='GT' |,
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op=='>' then return fractDiv(n.1 '/' d.1) > fractDiv(n.2 '/' d.2)
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when op=='LT' |,
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op=='<' then return fractDiv(n.1 '/' d.1) < fractDiv(n.2 '/' d.2)
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when op=='GE' | op=='≥' |,
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op=='>=' then return fractDiv(n.1 '/' d.1) >= fractDiv(n.2 '/' d.2)
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when op=='LE' | op=='≤' |,
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op=='<=' then return fractDiv(n.1 '/' d.1) <= fractDiv(n.2 '/' d.2)
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otherwise call err 'an illegal function:' op
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end /*select*/
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if t==0 then return 0; g=gcd(t,u); t=t/g; u=u/g
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if u==1 then return t
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return t'/'u
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/*─────────────────────────────general 1─line subs─────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────*/
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divisors: procedure; parse arg x 1 b; if x=1 then return 1; a=1; o=x//2; do j=2+o by 1+o while j*j<x; if x//j\==0 then iterate; a=a j; b=x%j b; end; if j*j==x then b=j b; return a b
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err: say; say '***error!***'; say; say f "detected" arg(1); say; exit 13
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gcd:procedure;$=;do i=1 for arg();$=$ arg(i);end;parse var $ x z .;if x=0 then x=z;x=abs(x);do j=2 to words($);y=abs(word($,j));if y=0 then iterate;do until _==0;_=x//y;x=y;y=_;end;end;return x
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isInt: return datatype(arg(1),'W')
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isNum: return datatype(arg(1),'N')
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lcm: procedure; $=; do j=1 for arg(); $=$ arg(j); end; x=abs(word($,1)); do k=2 to words($); !=abs(word($,k)); if !=0 then return 0; x=x*!/gcd(x,!); end; return x
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p: return word(arg(1),1)
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