Removal of items with duplicate data - c

Question

I'm writing a function that removes the consecutive items with duplicate data .
e.g
For example, passing in the list
->a->b->c->c->a->b->b->b->a->null
should result in
->a->b->c->a->b->a->null
The list item definition and function declaration are given below
struct litem {
char data;
litem* next;
};
Mo code looks like
int remove_dumplicates(litem *&list)
{
int count = 0;
struct litem * current = NULL;
current = list;
struct litem *deleteNode;
if (current == NULL ) return;
while(current->next != NULL)
{
if ( current->data == current->next->data) // check for the duplicates
{
count++;
deleteNode =current->next;
current>next= current->next->next;
delete deleteNode;
}
return (count);
}
}
Is this a correct way of achieving the desired result ?

Answer 1

I don't see current being incremented to current->next.
Take as an example a list with all unique elements a -> b -> c and see how your program works.
To fix this you need:
while(current->next != NULL) {
if ( current->data == current->next->data) {
// delete duplicates .
} else {
current = current -> next;
}
}// end-while
return (count);

Answer 2

You need to add an else inside the while loop to advance to the next node:
if( current-> data == current->next->data ) {
....
} else {
current = current->next;
}
Also the returns need to be fixed (the first should return 0 and the second should be moved outside the while loop).

Answer 3

Some quick observations:
The return (count) statement might be outside the while loop, otherwise the loop would be terminated prematurely.
A statement like current = current->next; is required inside the while loop. Otherwise, the loop would become an infinite loop.

Answer 4

current should move to current->next on no duplicate match.
Argument passed to the function should be merely *list (ie. a pointer to an element of type struct litem)
delete is a C++ keyword. Use free() instead.
The modified code:
int remove_duplicates(struct litem *list)
{
int count = 0;
struct litem * current = NULL;
current = list;
struct litem *deleteNode;
if (current == NULL ) return;
while(current->next != NULL)
{
if ( current->data == current->next->data)
{
count++;
deleteNode = current->next;
current->next= current->next->next;
free(deleteNode);
}
else
{
current = current->next;
}
}
return (count);
}

Answer 5

Try this:
int remove_duplicates(litem *&list)
{
int count = 0;
struct litem * current = NULL;
current = list;
struct litem *deleteNode;
if (current == NULL ) return 0;
while(current->next != NULL)
{
if (current->data == current->next->data) // check for the duplicates
{
count++;
deleteNode =current->next;
current->next= current->next->next;
delete deleteNode;
}
else
{
current = current->next;
}
}
return (count);
}