Hi all,

I'm pretty new to programming and need help to do a nested sort on a
linked list.

Basically I'm sorting a list of structures with names, classroom
number and floor level. I can sort in scending order any of the 3
values but I need to do a nested sort first with floor, followed by
classroom number and finally name.

Please tell me where I have gone wrong with this.
This is my linked list structure:

typedef struct tagCLASSROOMDATA
{
//added to display addtional info on nozzle configuration
char name[128];
short floor;
short roomnumber;
} CLASSROOMDATA;

typedef struct CLASSROOMFILEITEM
{
struct tagCLASSROOMITEM* next;
CLASSROOMDATA dt;

} CLASSROOMITEM;

I am using the algorithm below for my sorting:
sortClass( )
{
BINFILEITEM *p, *q, *r, *s, *temp ;
p = r = firstBinfileItem ;
while ( p -> next != NULL )
{
s = q = p -> next ;
while ( q != NULL )
{
if ( p -> dt.floor > q -> dt.floor )
{
if ( p -> next == q ) /* Adjacent Nodes */
{
if ( p == firstBinfileItem )
{
p -> next = q -> next ;
q -> next = p ;
temp = p ;
p = q ;
q = temp ;
firstBinfileItem = p ;
r = p ;
s = q ;
q = q -> next ;
}
else
{
p -> next = q -> next ;
q -> next = p ;
r -> next = q ;
temp = p ;
p = q ;
q = temp ;
s = q ;
q = q -> next ;
}
}
else
{
if ( p == firstBinfileItem )
{
temp = q -> next ;
q -> next = p -> next ;
p -> next = temp ;
s -> next = p ;
temp = p ;
p = q ;
q = temp ;
s = q ;
q = q -> next ;
firstBinfileItem = p ;
}
else
{
temp = q -> next ;
q -> next = p -> next ;
p -> next = temp ;
r -> next = q ;
s -> next = p ;
temp = p ;
p = q ;
q = temp ;
s = q ;
q = q -> next ;
}
}
}
else
{
s = q ;
q = q -> next ;
}
}
r = p ;
p = p -> next ;
}
}

Any help will be most appreciated, thanks!