Read the How to prepare for an interview series at my blog: http://se7so.blogspot.com/2014/01/how-to-prepare-for-interview.html

prob9.cpp

void remove(node* nd) {

	if(nd == NULL || nd->nxt == NULL) return; // It should be in the middle

	node* lnk1 = nd, *lnk2 = nd->nxt;
	
	while(lnk2->nxt) {
		swap(lnk1->d, lnk2->d);
		lnk1 = lnk1->nxt;
		lnk2 = lnk2->nxt;
	}
	
	swap(lnk1->d, lnk2->d);
	
	lnk1->nxt = NULL;
	delete lnk2;
}

/* a better solution, thanks to Manal Sadek */
void remove(node* nd) {
	if(nd == NULL || nd->nxt == NULL) return; // It should be in the middle
 
	node* lnk1 = nd, *lnk2 = nd->nxt;

	swap(lnk1->d, lnk2->d);
	lnk1->nxt = lnk2->nxt;
	delete lnk2;
}

Why u loop till then end of the list and delete the last element
what about this one

void remove(node* nd) {
 
if(nd == NULL || nd->nxt == NULL) return; // It should be in the middle
 
node* lnk1 = nd, *lnk2 = nd->nxt;

swap(lnk1->d, lnk2->d);
lnk1->nxt = lnk2->nxt;
delete lnk2;

}