Write a function to reverse a linked list.


/*
    Write a function to reverse a linked list. No double pointers please.
*/

#include

using namespace std;

struct node{int data; struct node *next;};

struct node* createlist()
{
    int counter=0;
    node *first, *temp, *last;
    first = (node*)malloc(sizeof(node));
    temp=first;
    cin>>temp->data;
    cout<<"Please enter the number of elements in the list that you want:    ";
    cin>>counter;
    while(counter!=0)
    {
    temp->next=(node*)malloc(sizeof(node));
    cout<<"Enter node data:    ";
    cin>>temp->data;
    last=temp;
    temp=temp->next;
    counter–;
    }
    last->next =NULL;
    delete(temp);
    return first;
}

void display(struct node *header)
{
    node *ptr;
    ptr=header;
    cout<<"The list now looks like:    ";
    while(ptr!=NULL)
    {
        cout<data<<"    ";
        ptr=ptr->next;
    }
    cout<<endl;
}

int lenlist(struct node *header)
{
    node *ptr;
    int len=0;
    ptr=header;
    while(ptr->next!=NULL)
    {
        len=len+1;
        ptr=ptr->next;
    };
    return len;
}
struct node* reverselist(struct node *header)
{
    int counter=5, tempHolder=0;
    node *temp, *ptr,*prev, *last;
    prev=NULL;
    ptr=header;
    //Obtain the length of the linked list
    counter=lenlist(header);
    while(counter!=0)
    {
        while(ptr->next!=NULL && ptr!=last)
        {
            if(ptr!=NULL)
            {
                tempHolder=ptr->data;
                ptr->data=(ptr->next)->data;
                (ptr->next)->data=tempHolder;
                prev=ptr;
            }
            else
            {
                cout<<"IF YOU SEE THIS, THE CODE IS FAULTY. The value of ptr is NULL for counter value "<<counter<<endl;
            }
            ptr=ptr->next;
        };
        ptr=header;
        last=prev;
        counter–;
    }
    return header;       
}

void main()
{
    node *header, *latest;
    node *header1;
    header=createlist();
    display(header);
    latest=reverselist(header);   
    display(latest);
}

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