void DeletePosition(node *first, node *last, int pos)
{
node prev = NULL, cur = *first, temp;
int i;
if (pos <= 0 || pos > count)
{
printf("\nYou entered an invalid position.");
return;
}
if (pos == 1) DeleteFront(first, last);
else if (pos == count) DeleteRear(first, last);
else
{
for (i = 1; i < pos; ++i)
{
prev = cur;
cur = cur->rlink;
}
temp = cur;
prev->rlink = cur->rlink;
cur->rlink->llink = prev;
free(temp);
}
--count;
}
int main()
{
struct Queue *q = CreateQueue();
InsertFront(q,1);
InsertFront(q,3);
InsertRear(q,0);
InsertRear(q,5);
printf("%d\n",DeleteFront(q)->element);
printf("%d\n",DeleteRear(q)->element);
}
void main()
{
node first = NULL, last = NULL;
int i, ch;
while (1)
{
printf("\nCIRCULAR LINKED LIST");
printf("\n1. INSERT\n2. DELETE\n3. DISPLAY\n4. EXIT");
printf("\nEnter your choice: ");
scanf("%d", &i);
//system("cls");
//clrscr();
switch (i)
{
case 1:
printf("\n1. Insert at front");
printf("\n2. Insert at rear");
printf("\nEnter your choice: ");
scanf("%d", &ch);
switch (ch)
{
case 1: InsertFront(&first, &last);
break;
case 2: InsertRear(&first, &last);
break;
default: printf("\n You chose an invalid option.");
}
break;
case 2: printf("\n1. Delete from front");
printf("\n2. Delete from rear");
printf("\nEnter your choice: ");
scanf("%d", &ch);
switch (ch)
{
case 1: DeleteFront(&first, &last);
break;
case 2: DeleteRear(&first, &last);
break;
default: printf("\n You chose an invalid option.");
}
break;
case 3: Display(&first, &last);
break;
case 4: return;
default: printf("\nInvalid choice. Try again.");
}
}
}
