// returns 1 on success, 0 if there are no cubes
extern int firstCube( int r, int n, int cube[] ) {
int origR = r;
memset(cube, -1, n*sizeof(*cube) );
while( r >= 2 ) {
cube[bdd_level2var(LEVEL(r))] = 0;
r = LOW(r);
}
if( r == 0 ) return nextCube( origR, n, cube );
else return 1;
}
// returns -1 if we're already at the last path, 0 if the next path is
// non-accepting, 1 if the next path is accepting
int nextPath( int r, int n, int cube[] ) {
int stack[n];
int top = 0;
int top0 = 0;
int i;
while( r >= 2 ) {
stack[top++] = r;
if( cube[bdd_level2var(LEVEL(r))] == 0 ) {
top0 = top;
r = LOW(r);
} else if( cube[bdd_level2var(LEVEL(r))] == 1 ) {
r = HIGH(r);
} else {
for( i = 0; i < n; i++ ) fprintf(stderr, "%d ", cube[i]);
fprintf( stderr, "internal error %d\n", cube[bdd_level2var(LEVEL(r))] );
*((int*)0) = 5;
}
}
// No zeros => we're already at the last path.
if( top0 == 0 ) return -1;
// Cut off the end of the path.
for( i = top0; i < top; i++ ) {
cube[bdd_level2var(LEVEL(stack[i]))] = -1;
}
// Switch the zero to a one.
r = stack[top0-1];
cube[bdd_level2var(LEVEL(r))] = 1;
r = HIGH(r);
// Fill in the other zeros.
while(1) {
if( r < 2 ) return r;
cube[bdd_level2var(LEVEL(r))] = 0;
r = LOW(r);
}
}
/* ML type: level -> varnum */
EXTERNML value mlbdd_bdd_level2var(value lev) /* ML */
{
return Val_long(bdd_level2var(Int_val(lev)));
}
