#include "nd.h"
ND nd_add_q(ND p1,ND p2)
{
int n,c,can;
ND r;
NM m1,m2,mr0,mr,s;
Q t;
if ( !p1 ) return p2;
else if ( !p2 ) return p1;
else {
can = 0;
for ( n = NV(p1), m1 = BDY(p1), m2 = BDY(p2), mr0 = 0; m1 && m2; ) {
c = DL_COMPARE(DL(m1),DL(m2));
switch ( c ) {
case 0:
addq(CQ(m1),CQ(m2),&t);
s = m1; m1 = NEXT(m1);
if ( t ) {
can++; NEXTNM2(mr0,mr,s); CQ(mr) = (t);
} else {
can += 2; FREENM(s);
}
s = m2; m2 = NEXT(m2); FREENM(s);
break;
case 1:
s = m1; m1 = NEXT(m1); NEXTNM2(mr0,mr,s);
break;
case -1:
s = m2; m2 = NEXT(m2); NEXTNM2(mr0,mr,s);
break;
}
}
if ( !mr0 )
if ( m1 ) mr0 = m1;
else if ( m2 ) mr0 = m2;
else return 0;
else if ( m1 ) NEXT(mr) = m1;
else if ( m2 ) NEXT(mr) = m2;
else NEXT(mr) = 0;
BDY(p1) = mr0;
SG(p1) = MAX(SG(p1),SG(p2));
LEN(p1) = LEN(p1)+LEN(p2)-can;
FREEND(p2);
return p1;
}
}