starting out with >>> C++ EARLY OBJECTS - Chapter 17 Programming Challenge #1 Us

Question

starting out with >>> C++ EARLY OBJECTS - Chapter 17 Programming Challenge #1 Using an appropriate definition of ListNode, design a simple linked list class with only two member functions and a default constructor: void add (double x); boolean isMember (double x); LinkedList ( ); The add function adds a new node containing x to the front (head) of the list, while the isMember function tests to see if the list contains a node with the value x. Test your linked list class by adding various numbers to the list and then testing for membership.

Explanation / Answer

#include <iostream>

#include <cstddef>

using std::cout;
using std::endl;

/*
A linked list is a list constructed using pointers. It is not fixed in
size and could grow and shrink while the program is running.

A typical defination of list nodes contains at least two parts, both the
content or date of each element and the pointer to the next element,
which is shown in the figure below.

+---------+
| Data | -----> holds the data of this element in the list.
+---------+
| pointer | -----> is a pointer to the next element in the list.
+---------+

***Attention***:
The pointer holds the address of the next element, not the address of the
data in the next element, even though they are the same in value sometimes.
And It should be set to NULL while acting as the last node of the list.


Implementation of the single linked list:
+---------+ --->+---------+ --->+---------+
| Data | | | Data | | | Data |
+---------+ | +---------+ | +---------+
| pointer |----- | pointer |----- | pointer |
+---------+ +---------+ +---------+
*/

/* definition of the list node class */
class Node
{
friend class LinkedList;
private:
int _value; /* data, can be any data type, but use integer for easiness */
Node *_pNext; /* pointer to the next node */
  
public:
/* Constructors with No Arguments */
Node(void)
: _pNext(NULL)
{ }
  
/* Constructors with a given value */
Node(int val)
: _value(val), _pNext(NULL)
{ }
  
/* Constructors with a given value and a link of the next node */
Node(int val, Node* next)
: _value(val), _pNext(next)
{}
  
/* Getters */
int getValue(void)
{ return _value; }
  
Node* getNext(void)
{ return _pNext; }
};

/* definition of the linked list class */
class LinkedList
{
private:
/* pointer of head node */
Node *_pHead;
/* pointer of tail node */
Node *_pTail;
  
public:
/* Constructors with a given value of a list node */
LinkedList(int val);
/* Destructor */
~LinkedList(void);
  
/* Function to append a node to the end of a linked list */
void add(double val);
  
/* Function to search a node with a given value,
and if succeeded return the node */
Node* isMember(double val);
};

LinkedList::LinkedList(int val)
{
/* Create a new node, acting as both the head and tail node */
_pHead = new Node(val);
_pTail = _pHead;
}

LinkedList::~LinkedList()
{
/*
* Leave it empty temporarily.
* It will be described in detail in the example "How to delete a linkedlist".
*/
}

void LinkedList::add(double val)
{
/* The list is empty? */
if (_pHead == NULL) {
/* the same to create a new list with a given value */
_pTail = _pHead = new Node(val);
}
else
{
/* Append the new node to the tail */
_pTail->_pNext = new Node(val);
/* Update the tail pointer */
_pTail = _pTail->_pNext;
}
}

Node* LinkedList::isMember(double val)
{
Node* pNode = _pHead;
  
/* traverse the list */
while (pNode != NULL) {
/* Target! */
if(pNode->_value == val)
{
return pNode;
}
/* move to the next one */
pNode = pNode->_pNext;
}
return NULL;
}

int main(int argc, const char * argv[])
{
/* Create a list with only one node */
LinkedList list(1);
/* Append 3 nodes to the end of the list */
list.add(2);
list.add(3);
list.add(4);
  
cout << "This list includes 4 nodes with values: 1 2 3 4" << endl;
cout << endl;
  
Node* node;
/* Search the node with value 3 */
cout << "Searching a node with value 3" << endl;
node = list.isMember(3);
/* output the result */
if (node != NULL)
cout << "Result: Find the node with value " << node->getValue() << endl;
  
else
cout << "Result: Cannot find the node with value 3" << endl;
cout << endl;
  
/* Search the node with value 5 */
cout << "Searching a node with value 5" << endl;
node = list.isMember(5);
/* output the result */
if (node != NULL)
cout << "Result: Find the node with value " << node->getValue() << endl;
  
else
cout << "Result: Cannot find the node with value 5" << endl;
  
return 0;
}

Related Questions

Navigate

• Browse (All)
• Browse S
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.