Blk*
mult(Blk *p, Blk *q)
{
Blk *mp, *mq, *mr;
int sign, offset, carry;
int cq, cp, mt, mcr;
offset = sign = 0;
fsfile(p);
mp = p;
if(sfbeg(p) == 0) {
if(sbackc(p)<0) {
mp = copy(p,length(p));
chsign(mp);
sign = ~sign;
}
}
fsfile(q);
mq = q;
if(sfbeg(q) == 0){
if(sbackc(q)<0) {
mq = copy(q,length(q));
chsign(mq);
sign = ~sign;
}
}
mr = salloc(length(mp)+length(mq));
zero(mr);
rewind(mq);
while(sfeof(mq) == 0) {
cq = sgetc(mq);
rewind(mp);
rewind(mr);
mr->rd += offset;
carry=0;
while(sfeof(mp) == 0) {
cp = sgetc(mp);
mcr = sfeof(mr)?0:slookc(mr);
mt = cp*cq + carry + mcr;
carry = mt/100;
salterc(mr,mt%100);
}
offset++;
if(carry != 0) {
mcr = sfeof(mr)?0:slookc(mr);
salterc(mr,mcr+carry);
}
}
if(sign < 0) {
chsign(mr);
}
if(mp != p)
release(mp);
if(mq != q)
release(mq);
return(mr);
}
Blk*
dcsqrt(Blk *p)
{
Blk *t, *r, *q, *s;
int c, n, nn;
n = length(p);
fsfile(p);
c = sbackc(p);
if((n&1) != 1)
c = c*100+(sfbeg(p)?0:sbackc(p));
n = (n+1)>>1;
r = salloc(n);
zero(r);
seekc(r,n);
nn=1;
while((c -= nn)>=0)
nn+=2;
c=(nn+1)>>1;
fsfile(r);
backc(r);
if(c>=100) {
c -= 100;
salterc(r,c);
sputc(r,1);
} else
salterc(r,c);
for(;;){
q = div(p,r);
s = add(q,r);
release(q);
release(rem);
q = div(s,sqtemp);
release(s);
release(rem);
s = copy(r,length(r));
chsign(s);
t = add(s,q);
release(s);
fsfile(t);
nn = sfbeg(t)?0:sbackc(t);
if(nn>=0)
break;
release(r);
release(t);
r = q;
}
release(t);
release(q);
release(p);
return(r);
}
Blk*
add(Blk *a1, Blk *a2)
{
Blk *p;
int carry, n, size, c, n1, n2;
size = length(a1)>length(a2)?length(a1):length(a2);
p = salloc(size);
rewind(a1);
rewind(a2);
carry=0;
while(--size >= 0) {
n1 = sfeof(a1)?0:sgetc(a1);
n2 = sfeof(a2)?0:sgetc(a2);
n = n1 + n2 + carry;
if(n>=100) {
carry=1;
n -= 100;
} else
if(n<0) {
carry = -1;
n += 100;
} else
carry = 0;
sputc(p,n);
}
if(carry != 0)
sputc(p,carry);
fsfile(p);
if(sfbeg(p) == 0) {
c = 0;
while(sfbeg(p) == 0 && (c = sbackc(p)) == 0)
;
if(c != 0)
salterc(p,c);
truncate(p);
}
fsfile(p);
if(sfbeg(p) == 0 && sbackc(p) == -1) {
while((c = sbackc(p)) == 99) {
if(c == -1)
break;
}
skipc(p);
salterc(p,-1);
truncate(p);
}
return(p);
}
void
chsign(Blk *p)
{
int carry;
char ct;
carry=0;
rewind(p);
while(sfeof(p) == 0) {
ct=100-slookc(p)-carry;
carry=1;
if(ct>=100) {
ct -= 100;
carry=0;
}
salterc(p,ct);
}
if(carry != 0) {
sputc(p,-1);
fsfile(p);
backc(p);
ct = sbackc(p);
if(ct == 99 /*&& !sfbeg(p)*/) {
truncate(p);
sputc(p,-1);
}
} else{
fsfile(p);
ct = sbackc(p);
if(ct == 0)
truncate(p);
}
return;
}
void
chsign(struct blk *p)
{
register int carry;
register char ct;
carry=0;
rewind(p);
while(sfeof(p) == 0){
ct=100-slookc(p)-carry;
carry=1;
if(ct>=100){
ct -= 100;
carry=0;
}
salterc(p,ct);
}
if(carry != 0){
sputc(p,-1);
fsfile(p);
sbackc(p);
ct = sbackc(p);
if(ct == 99){
truncate(p);
sputc(p,-1);
}
}
else{
fsfile(p);
ct = sbackc(p);
if(ct == 0)truncate(p);
}
return;
}
Blk*
div(Blk *ddivd, Blk *ddivr)
{
int divsign, remsign, offset, divcarry,
carry, dig, magic, d, dd, under, first;
long c, td, cc;
Blk *ps, *px, *p, *divd, *divr;
dig = 0;
under = 0;
divcarry = 0;
rem = 0;
p = salloc(0);
if(length(ddivr) == 0) {
pushp(ddivr);
Bprint(&bout,"divide by 0\n");
return(p);
}
divsign = remsign = first = 0;
divr = ddivr;
fsfile(divr);
if(sbackc(divr) == -1) {
divr = copy(ddivr,length(ddivr));
chsign(divr);
divsign = ~divsign;
}
divd = copy(ddivd,length(ddivd));
fsfile(divd);
if(sfbeg(divd) == 0 && sbackc(divd) == -1) {
chsign(divd);
divsign = ~divsign;
remsign = ~remsign;
}
offset = length(divd) - length(divr);
if(offset < 0)
goto ddone;
seekc(p,offset+1);
sputc(divd,0);
magic = 0;
fsfile(divr);
c = sbackc(divr);
if(c < 10)
magic++;
c = c * 100 + (sfbeg(divr)?0:sbackc(divr));
if(magic>0){
c = (c * 100 +(sfbeg(divr)?0:sbackc(divr)))*2;
c /= 25;
}
while(offset >= 0) {
first++;
fsfile(divd);
td = sbackc(divd) * 100;
dd = sfbeg(divd)?0:sbackc(divd);
td = (td + dd) * 100;
dd = sfbeg(divd)?0:sbackc(divd);
td = td + dd;
cc = c;
if(offset == 0)
td++;
else
cc++;
if(magic != 0)
td = td<<3;
dig = td/cc;
under=0;
if(td%cc < 8 && dig > 0 && magic) {
dig--;
under=1;
}
rewind(divr);
rewind(divxyz);
carry = 0;
while(sfeof(divr) == 0) {
d = sgetc(divr)*dig+carry;
carry = d / 100;
salterc(divxyz,d%100);
}
salterc(divxyz,carry);
rewind(divxyz);
seekc(divd,offset);
carry = 0;
while(sfeof(divd) == 0) {
d = slookc(divd);
d = d-(sfeof(divxyz)?0:sgetc(divxyz))-carry;
carry = 0;
if(d < 0) {
d += 100;
carry = 1;
}
salterc(divd,d);
}
divcarry = carry;
backc(p);
salterc(p,dig);
backc(p);
fsfile(divd);
d=sbackc(divd);
if((d != 0) && /*!divcarry*/ (offset != 0)) {
d = sbackc(divd) + 100;
salterc(divd,d);
}
if(--offset >= 0)
divd->wt--;
}
if(under) { /* undershot last - adjust*/
px = copy(divr,length(divr)); /*11/88 don't corrupt ddivr*/
chsign(px);
ps = add(px,divd);
fsfile(ps);
if(length(ps) > 0 && sbackc(ps) < 0) {
release(ps); /*only adjust in really undershot*/
} else {
release(divd);
salterc(p, dig+1);
divd=ps;
}
}
if(divcarry != 0) {
salterc(p,dig-1);
salterc(divd,-1);
ps = add(divr,divd);
release(divd);
divd = ps;
}
rewind(p);
divcarry = 0;
while(sfeof(p) == 0){
d = slookc(p)+divcarry;
divcarry = 0;
if(d >= 100){
d -= 100;
divcarry = 1;
}
salterc(p,d);
}
if(divcarry != 0)salterc(p,divcarry);
fsfile(p);
while(sfbeg(p) == 0) {
if(sbackc(p) != 0)
break;
truncate(p);
}
if(divsign < 0)
chsign(p);
fsfile(divd);
while(sfbeg(divd) == 0) {
if(sbackc(divd) != 0)
break;
truncate(divd);
}
ddone:
if(remsign<0)
chsign(divd);
if(divr != ddivr)
release(divr);
rem = divd;
return(p);
}
struct blk *
div(struct blk *ddivd,struct blk *ddivr)
{
int divsign,remsign,offset,divcarry = 0;
int carry, dig = 0,magic,d = 0,dd;
long c,td,cc;
struct blk *ps;
register struct blk *p,*divd,*divr;
rem = 0;
p = salloc(0);
if(length(ddivr) == 0){
pushp(ddivr);
printf("divide by 0\n");
return NULL;
}
divsign = remsign = 0;
divr = ddivr;
fsfile(divr);
if(sbackc(divr) == -1){
divr = copy(ddivr,length(ddivr));
chsign(divr);
divsign = ~divsign;
}
divd = copy(ddivd,length(ddivd));
fsfile(divd);
if(sfbeg(divd) == 0 && sbackc(divd) == -1){
chsign(divd);
divsign = ~divsign;
remsign = ~remsign;
}
offset = length(divd) - length(divr);
if(offset < 0)goto ddone;
seekc(p,offset+1);
sputc(divd,0);
magic = 0;
fsfile(divr);
c = sbackc(divr);
if(c<10)magic++;
c = c*100 + (sfbeg(divr)?0:sbackc(divr));
if(magic>0){
c = (c*100 +(sfbeg(divr)?0:sbackc(divr)))*2;
c /= 25;
}
while(offset >= 0){
fsfile(divd);
td = sbackc(divd)*100;
dd = sfbeg(divd)?0:sbackc(divd);
td = (td+dd)*100;
dd = sfbeg(divd)?0:sbackc(divd);
td = td+dd;
cc = c;
if(offset == 0)td += 1;
else cc += 1;
if(magic != 0)td = td<<3;
dig = td/cc;
rewind(divr);
rewind(divxyz);
carry = 0;
while(sfeof(divr) == 0){
d = sgetc(divr)*dig+carry;
carry = d / 100;
salterc(divxyz,d%100);
}
salterc(divxyz,carry);
rewind(divxyz);
seekc(divd,offset);
carry = 0;
while(sfeof(divd) == 0){
d = slookc(divd);
d = d-(sfeof(divxyz)?0:sgetc(divxyz))-carry;
carry = 0;
if(d < 0){
d += 100;
carry = 1;
}
salterc(divd,d);
}
divcarry = carry;
sbackc(p);
salterc(p,dig);
sbackc(p);
if(--offset >= 0){
if(d > 0){
sbackc(divd);
dd=sbackc(divd);
salterc(divd,dd+100);
}
divd->wt--;
}
}
if(divcarry != 0){
salterc(p,dig-1);
salterc(divd,-1);
ps = add(divr,divd);
release(divd);
divd = ps;
}
rewind(p);
divcarry = 0;
while(sfeof(p) == 0){
d = slookc(p)+divcarry;
divcarry = 0;
if(d >= 100){
d -= 100;
divcarry = 1;
}
salterc(p,d);
}
if(divcarry != 0)salterc(p,divcarry);
fsfile(p);
while(sfbeg(p) == 0){
if(sbackc(p) == 0)truncate(p);
else break;
}
if(divsign < 0)chsign(p);
fsfile(divd);
while(sfbeg(divd) == 0){
if(sbackc(divd) == 0)truncate(divd);
else break;
}
ddone:
if(remsign<0)chsign(divd);
if(divr != ddivr)release(divr);
rem = divd;
return(p);
}
