How to access a linked list pointed to by a void pointer

Question

[enter image description here][1]I just started leaning C++ and I have been given a course project.

The initial data is located into a data structure consisting of arrays of pointers, headers and items

typedef struct headerA
{
    void* pItems;  // Pointer to the linked list of items. 
                   // Items may be of types ITEM1...ITEM10.
    char cBegin;   // The linked list contains objects in which
                   // the first letter of the second word
                   // of ID cBegin.
    struct headerA* pNext;
} HEADER_A;

typedef struct item1
{
    char* pID;
    unsigned long int Code;
    char* pTime; // formatted as hh::mm::ss
    struct item1* pNext;
} ITEM1;
 
HEADER_A * *p = GetStruct3(3, 100);
ITEM1* pNewItem = (ITEM1*)GetItem(1); // generates a stand-alone item of type iItem and returns the 
//pointer to it.
int i = 0;
while (p[i] != NULL) // p is a an array of pointers to linked list of Headers
{
    pNew = p[i]->pNext; // accessing the first Header. Each header points to a 
    //linked list of Items
    while (pNew)   // looping through the linked list of each header
    {
        pNew->pItems = pNewItem; // This is where I have a problem. how to access 
      //the void * pItems

        while (pNewItem) // looping through the linked list of Items
        {
            cout << pNewItem->Code << pNewItem->pID << pNewItem->pTime << endl;
            pNewItem = pNewItem->pNext;
        }
        pNew = pNew->pNext;
    }
    i++;
}

My problem is, I am unable to properly access the linked list of Items in each Header.

void* pItems;  // Pointer to the linked list of items.

When I used a typecast pNewItem = (ITEM1*)pNew->pItems; , it prints only the first item in the first header, and the while loops don't work anymore.

How do I access the linked list of ITEM in each header pointed to by a void* pointer, using C++ style?

 HEADER_A **p = GetStruct3(3, 100);
ITEM1* pNewItem = (ITEM1*)GetItem(1);
ITEM3* pNewItem2 = (ITEM3*)GetItem(3);
HEADER_A* pNew;
 int i = 0;
while (p[i] != NULL)
{  
    pNew = p[i]->pNext;
    cout << i << endl;
    while (pNew)
    {
        cout << i << endl;
        cout << pNew->cBegin << endl;
        pNew->pItems = pNewItem;
        pNewItem12 = pNewItem;
        
        while (pNewItem12)
        {
            cout << pNewItem12->Code << pNewItem12->pID << pNewItem12->pTime 
   << endl;
            cout << " we are now here12" << endl;
            pNewItem12 = pNewItem12->pNext;   
        }
        cout << " we are now her1234e" << endl;
        pNew = pNew->pNext;
    }
    i++;

This is sample output from the code snippet above

0
0
T
1686042807Lime Green10:34:47
we are now here12
we are now her1234e
0
W
1686042807Lime Green10:34:47
we are now here12
we are now her1234e
1
1
G
1686042807Lime Green10:34:47
we are now here12
we are now her1234e
1

This is not the complete output but it shows that it is looping through the while loops but it is printing the same item that i generated in the beginning not the ones in the structure, This is because I am having difficulties going through the list of linked list of Item pointed to by void* pItem in each Header [1]: https://i.stack.imgur.com/Wh3av.jpg

Answer 1

I noticed my error. The datatype of the pointer I was typecasting to was not the same as the datatype of the Items in the linked list pointed to by the void pointer.