Question

// C++ Doubly linked list

class clinknode{

friend class DList;

public:

    clinknode(){next = prev=0;data =0;}

protected:

    clinknode *next;

    clinknode *prev;

    int data;

}

class DList{

public:

DList(){first = last = 0;}

void insertFront(int key);

bool found(int key){ return search(key)!=0;}

void deleteAll(int key);

// other list functions...

private:

clinknode *search(int);

clinknode *first;

clinknode *last;

}

(20 points) Write the code for the deleteAll (int key) member function. It takes a key value and deletes all of the data in the list with that value. Make sure to preserve the integrity of the list. If no member with that value is in the list, this function should do nothing.

Answer 1

// C++ Doubly linked list

class clinknode{

friend class DList;

public:

clinknode(){next = prev=0;data =0;}

protected:

clinknode *next;

clinknode *prev;

int data;

}

class DList{

public:

DList(){first = last = 0;}

void insertFront(int key);

bool found(int key){ return search(key)!=0;}

void deleteAll(int key);

// other list functions...

private:

clinknode *search(int);

clinknode *first;

clinknode *last;

}
void DList::deleteAll(int key)
{
   clinknode *temp = first;
  
   //seraching for key and removing
   while(temp!=NULL)
   {
       if(temp->data==key)//if found //then removing it
       {
           if(temp->prev==NULL)//if it is first node
           {
               first=first->next;   //then moving first node
           }
           else
           {
               temp->prev=temp->next;//delinking that node  
           }  
       }
      
       temp=temp->next;  
   }
  
}