Good evening everyone.
I'm a CIS student and I wrote an implementation for a Linked List code while studying for my test tomorrow.
Everything seems to work perfectly except that there are four problems that need solutions:
CODE
# include <iostream>
using namespace std;
# include <cstdlib>
# include <ctime>
# include <assert.h>
template <class E>
class LinkedList
{
protected:
struct node
{
E data;
node *next;
};
node *myCurrent;
node *myPrevious;
node *myFirst;
int mySize;
node* getNode(const E &e)
{
node* newNode = new node;
assert (newNode !=0 );
newNode -> data = e;
newNode -> next = 0;
return newNode;
}
void removeNode(E val)
{
node* remv;
remv = myCurrent;
myPrevious -> next = myCurrent->next;
myCurrent -> next = NULL;
myCurrent = myPrevious;
delete remv; /*next = NULL*/
myCurrent = myCurrent -> next;
//nextNode();
}
public:
LinkedList<E>()
: myCurrent(0), myPrevious(0)
{
mySize = 0;
myFirst = 0;
}
E access()
{
assert (myCurrent != 0);
return myCurrent -> data;
}
void nextNode()
{
assert (myCurrent != 0);
myPrevious = myCurrent;
myCurrent = myCurrent -> next;
}
void insert (const E &e1)
{
node* newnode = getNode(e1);
if (mySize != 0 || myCurrent == myFirst)
myFirst = newnode;
else
myPrevious->next = newnode;
newnode->next = myCurrent;
myCurrent = newnode;
mySize++;
}
void First()
{
assert (mySize != 0);
myCurrent = myFirst;
myPrevious = NULL;
}
LinkedList( LinkedList& lcopy)
//:mySize(0),myCurrent(0),myPrevious(0),myFirst(0)
{
lcopy.First();
while (lcopy.myCurrent->next != NULL)
{
insert (lcopy.myCurrent->data);
lcopy.nextNode();
nextNode();
lcopy.mySize++;
}
/*mySize = lcopy.mySize;*/
};
void printList()
{
if (mySize == 0 || myFirst == NULL)
cout << "List is empty. " << '\n';
else
First();
for (int i = 0; i < mySize; i++)
{
cout << myCurrent -> data << ' ';
nextNode();
}
}
void removeValue(E v)
{
First();
for (int i = 0; i < mySize; i++)
{
if (myCurrent -> data == v)
{
removeNode(v);
}
//myPrevious -> next = myCurrent->next;
//delete myCurrent -> next; /*next = NULL*/
//myCurrent = myPrevious -> next;
//nextNode();
}
}
};
void main()
{
LinkedList<int> l1;
/*LinkedList<int> l2(l1);*/
srand(time(0));
int b = 1;
for (int i = 14; i >= 1; i--)
{
l1.insert(b);
b++;
l1.nextNode();
}
l1.printList();
l1.removeValue(4);
cout << '\n';
cout << '\n';
l1.printList();
}
First one: is in the copy constructor, it produces a runtime error.
Second one: in either the nextNode() function or the insert() function, a runtime error occurs when
attempting to call the nextNode() function from the main();
Third one: is with printList() function, it prints the elements of the list oppositely (i.e., 54321 instead of 12345).
Fourth one: Is in the removeNode() function, it doesn't produce any errors, but it still doesn't work.
Please help me.
Thanks.
This post has been edited by CIS_Soldier87: 30 Oct, 2007 - 06:54 AM
30 Oct, 2007 - 05:51 AM
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