Obj CollectPolycyc (
Obj pcp,
Obj list,
Obj word )
{
Int ngens = INT_INTOBJ( CONST_ADDR_OBJ(pcp)[ PC_NUMBER_OF_GENERATORS ] );
Obj commute = CONST_ADDR_OBJ(pcp)[ PC_COMMUTE ];
Obj gens = CONST_ADDR_OBJ(pcp)[ PC_GENERATORS ];
Obj igens = CONST_ADDR_OBJ(pcp)[ PC_INVERSES ];
Obj pow = CONST_ADDR_OBJ(pcp)[ PC_POWERS ];
Obj ipow = CONST_ADDR_OBJ(pcp)[ PC_INVERSEPOWERS ];
Obj exp = CONST_ADDR_OBJ(pcp)[ PC_EXPONENTS ];
Obj wst = CFTLState()->WORD_STACK;
Obj west = CFTLState()->WORD_EXPONENT_STACK;
Obj sst = CFTLState()->SYLLABLE_STACK;
Obj est = CFTLState()->EXPONENT_STACK;
Obj conj=0, iconj=0; /*QQ initialize to please compiler */
Int st;
Int g, syl, h, hh;
Obj e, ee, ge, mge, we, s, t;
Obj w, x = (Obj)0, y = (Obj)0;
if( LEN_PLIST(word) == 0 ) return (Obj)0;
if( LEN_PLIST(list) < ngens ) {
ErrorQuit( "vector too short", 0L, 0L );
return (Obj)0;
}
if( LEN_PLIST(word) % 2 != 0 ) {
ErrorQuit( "Length of word odd", 0L, 0L );
return (Obj)0;
}
st = 0;
PUSH_STACK( word, INTOBJ_INT(1) );
while( st > 0 ) {
w = ELM_PLIST( wst, st );
syl = INT_INTOBJ( ELM_PLIST( sst, st ) );
g = INT_INTOBJ( ELM_PLIST( w, syl ) );
if( st > 1 && syl==1 && g == GET_COMMUTE(g) ) {
/* Collect word^exponent in one go. */
e = ELM_PLIST( west, st );
/* Add in. */
AddIn( list, w, e );
/* Reduce. */
for( h = g; h <= ngens; h++ ) {
s = ELM_PLIST( list, h );
if( IS_INT_ZERO( s ) ) continue;
y = (Obj)0;
if( (e = GET_EXPONENT( h )) != (Obj)0 ) {
if( !LtInt( s, e ) ) {
t = ModInt( s, e );
SET_ELM_PLIST( list, h, t ); CHANGED_BAG( list );
if( (y = GET_POWER( h )) ) e = QuoInt( s, e );
}
else if( LtInt( s, INTOBJ_INT(0) ) ) {
t = ModInt( s, e );
SET_ELM_PLIST( list, h, t ); CHANGED_BAG( list );
if( (y = GET_IPOWER( h )) ) {
e = QuoInt( s, e );
if( !IS_INT_ZERO( t ) ) e = DiffInt( e, INTOBJ_INT(1) );
e = AInvInt(e);
}
}
}
if( y != (Obj)0 ) AddIn( list, y, e );
}
st--;
}
else {
if( g == GET_COMMUTE( g ) ) {
s = ELM_PLIST( list, g );
t = ELM_PLIST( est, st );
C_SUM_FIA( ge, s, t );
SET_ELM_PLIST( est, st, INTOBJ_INT(0) );
}
else {
/* Assume that the top of the exponent stack is non-zero. */
e = ELM_PLIST( est, st );
if( LtInt( INTOBJ_INT(0), e ) ) {
C_DIFF_FIA( ee, e, INTOBJ_INT(1) ); e = ee;
SET_ELM_PLIST( est, st, e ); CHANGED_BAG( est );
conj = CONST_ADDR_OBJ(pcp)[PC_CONJUGATES];
iconj = CONST_ADDR_OBJ(pcp)[PC_INVERSECONJUGATES];
C_SUM_FIA( ge, ELM_PLIST( list, g ), INTOBJ_INT(1) );
}
else {
C_SUM_FIA( ee, e, INTOBJ_INT(1) ); e = ee;
SET_ELM_PLIST( est, st, e ); CHANGED_BAG( est );
conj = CONST_ADDR_OBJ(pcp)[PC_CONJUGATESINVERSE];
iconj = CONST_ADDR_OBJ(pcp)[PC_INVERSECONJUGATESINVERSE];
C_DIFF_FIA( ge, ELM_PLIST( list, g ), INTOBJ_INT(1) );
}
}
SET_ELM_PLIST( list, g, ge ); CHANGED_BAG( list );
/* Reduce the exponent. We delay putting the power onto the
stack until all the conjugates are on the stack. The power is
stored in y, its exponent in ge. */
y = (Obj)0;
if( (e = GET_EXPONENT( g )) ) {
if( !LtInt( ge, e ) ) {
mge = ModInt( ge, e );
SET_ELM_PLIST( list, g, mge ); CHANGED_BAG( list );
if( (y = GET_POWER( g )) ) ge = QuoInt( ge, e );
}
else if( LtInt( ge, INTOBJ_INT(0) ) ) {
mge = ModInt( ge, e );
SET_ELM_PLIST( list, g, mge ); CHANGED_BAG( list );
if( (y = GET_IPOWER( g )) ) {
ge = QuoInt( ge, e );
if( !IS_INT_ZERO( mge ) )
ge = DiffInt( ge, INTOBJ_INT(1) );
ge = AInvInt(ge);
}
}
}
hh = h = GET_COMMUTE( g );
/* Find the place where we start to collect. */
for( ; h > g; h-- ) {
e = ELM_PLIST( list, h );
if( !IS_INT_ZERO(e) ) {
if( LtInt( INTOBJ_INT(0), e ) ) {
if( GET_CONJ( h, g ) ) break;
}
else {
if( GET_ICONJ( h, g ) ) break;
}
}
}
/* Put those onto the stack, if necessary. */
if( h > g || y != (Obj)0 )
for( ; hh > h; hh-- ) {
e = ELM_PLIST( list, hh );
if( !IS_INT_ZERO(e) ) {
SET_ELM_PLIST( list, hh, INTOBJ_INT(0) );
if( LtInt( INTOBJ_INT(0), e ) ) {
x = ELM_PLIST( gens, hh );
}
else {
x = ELM_PLIST( igens, hh );
C_PROD_FIA( ee, e, INTOBJ_INT(-1) ); e = ee;
}
PUSH_STACK( x, e );
}
}
for( ; h > g; h-- ) {
e = ELM_PLIST( list, h );
if( !IS_INT_ZERO(e) ) {
SET_ELM_PLIST( list, h, INTOBJ_INT(0) );
x = (Obj)0;
if( LtInt( INTOBJ_INT(0), e ) ) x = GET_CONJ( h, g );
else x = GET_ICONJ( h, g );
if( x == (Obj)0 ) {
if( LtInt( INTOBJ_INT(0), e ) ) x = ELM_PLIST( gens, h );
else x = ELM_PLIST( igens, h );
}
if( LtInt( e, INTOBJ_INT(0) ) ) {
C_PROD_FIA( ee, e, INTOBJ_INT(-1) ); e = ee;
}
PUSH_STACK( x, e );
}
}
if( y != (Obj)0 ) PUSH_STACK( y, ge );
}
while( st > 0 && IS_INT_ZERO( ELM_PLIST( est, st ) ) ) {
w = ELM_PLIST( wst, st );
syl = INT_INTOBJ( ELM_PLIST( sst, st ) ) + 2;
if( syl > LEN_PLIST( w ) ) {
we = DiffInt( ELM_PLIST( west, st ), INTOBJ_INT(1) );
if( EqInt( we, INTOBJ_INT(0) ) ) { st--; }
else {
SET_ELM_PLIST( west, st, we );
SET_ELM_PLIST( sst, st, INTOBJ_INT(1) );
SET_ELM_PLIST( est, st, ELM_PLIST( w, 2 ) );
CHANGED_BAG( west ); CHANGED_BAG( est );
}
}
else {
SET_ELM_PLIST( sst, st, INTOBJ_INT(syl) );
SET_ELM_PLIST( est, st, ELM_PLIST( w, syl+1 ));
CHANGED_BAG( est );
}
}
}
return (Obj)0;
}
ModInt operator*(ModInt rhs) const {
return ModInt(*this) *= rhs;
}
ModInt operator/(ModInt rhs) const {
return ModInt(*this) /= rhs;
}
ModInt operator-(ModInt rhs) const {
return ModInt(*this) -= rhs;
}
ModInt operator+(ModInt rhs) const {
return ModInt(*this) += rhs;
}
ModInt operator*(const ModInt& o) const {
return ModInt(*this) *= o;
}
ModInt operator-(const ModInt& o) const {
return ModInt(*this) -= o;
}
ModInt operator+(const ModInt& o) const {
return ModInt(*this) += o;
}
