bigint* copybigint(bigint* from, bigint* to)
{
int n = abs(from->size); digit *f, *t;
if (to==NULL) to = mkbigint(n);
else if (to->allocsize<n) { freemem(to); to=mkbigint(n); }
to->size = from->size;
for (f=from->data, t=to->data; n>0; --n) *t++=*f++;
return to;
}
object Factor(bigint* num)
{ num=copybigint(num,NULL);
if (num->size<0) { Printf("- "); num->size=-num->size; }
{ bigint* temp=mkbigint(num->size); _digit p; int i=0;
if (num->size==0) { Printf("0"); goto quit; }
for (p=2; p<=trial_limit; p+= inc[i++])
{ if (i==array_size(inc)) i=3; /* after |37-31| wrap to difference |11-7| */
if (copybigint(num,temp),div1(temp,p)==0)
{ _index n; _digit pn=p; int e=1; copybigint(temp,num);
for (n=1; pn<=MaxDigit/p; ++n) pn*=p; /* highest $p^n$ fitting in |_digit| */
for (; div1(temp,pn)==0; e+=n) copybigint(temp,num);
/* find factors $p^n$ */
if (n>1) /* then there might be some factors |p| left */
for (copybigint(num,temp); div1(temp,p)==0; ++e) copybigint(temp,num);
/* factors |p| */
Printf("%ld",(long)p); if (e>1) Printf("^%ld",(long)e);
if (cmp1(num,1)==0) goto quit; /* last factor was found */
Printf(" * ");
}
}
printbigint(num,0);
if (num->size>2) Printf(" (Last factor need not be a prime)");
quit: Printf("\n");
freemem(num); freemem(temp);
}
return (object) NULL;
}
pointer ICONVOPEN(context *ctx, int n, pointer *argv)
{ int cd;
ckarg(2);
if (!isstring(argv[0])) error (E_NOSTRING, argv[0]);
if (!isstring(argv[1])) error (E_NOSTRING, argv[1]);
cd=iconv_open(argv[0]->c.str.chars, argv[1]->c.str.chars);
return(mkbigint(cd));}
