我使用以下源代码创建了一个链表程序，
#include <iostream>
using namespace std;
struct Node
{
int data;
Node *next;
};
struct HeadNode
{
int count;
Node *headPtr;
};
class LinkedList
{
public:
LinkedList();
~LinkedList();
void addToHead( int );
bool removeFromHead();
// bool addToTail ( int );
// bool removeFromTail();
void addNode ( int );
bool deleteNode ( int );
void deleteAllNodes();
bool isEmpty();
int getNoOfNodes();
void displayAllNodes();
private:
int dataCmp ( int, int );
void displayNode ( Node* );
HeadNode head;
};
LinkedList::LinkedList()
{
head.count = 0;
head.headPtr = NULL;
return;
}
LinkedList::~LinkedList()
{
deleteAllNodes();
return;
}
void LinkedList::addToHead ( int newData )
{
Node *pNew = new Node;
pNew -> data = newData;
pNew -> next = head.headPtr;
head.headPtr = pNew;
head.count++;
}
bool LinkedList::removeFromHead()
{
bool exit;
Node *temp;
if ( head.headPtr )
{
temp = head.headPtr;
head.headPtr = head.headPtr -> next;
delete temp;
head.count--;
exit = true; // returns true if it's successful
}
else
exit = false; // returns false if it's not successful
return exit;
}
/*
bool LinkedList::addToTail( int )
{
}
bool Linked::removeFromTail();
{
}
*/
void LinkedList::addNode ( int newData )
{
Node *pNew = new Node,
*pPre = NULL,
*pCur = head.headPtr;
pNew -> data = newData;
while ( pCur && dataCmp( pNew -> data, pCur -> data ) >= 0 )
{
pPre = pCur;
pCur = pCur -> next;
}
if ( pPre )
{
pNew -> next = pPre -> next;
pPre -> next = pNew;
head.count++;
}
else
{
pNew -> next = head.headPtr;
head.headPtr = pNew;
head.count++;
}
}
bool LinkedList::deleteNode( int data )
{
bool exit;
Node *pPre = NULL,
*pCur = head.headPtr;
while ( pCur && dataCmp( pCur -> data, data ) < 0 )
{
pPre = pCur;
pCur = pCur -> next;
}
if ( pCur && dataCmp( pCur -> data, data ) == 0 )
{
if ( pPre )
{
pPre -> next = pCur -> next;
delete pCur;
head.count--;
exit = true; // return true if successful
}
else
{
head.headPtr = pCur -> next;
delete pCur;
head.count--;
exit = true; // return true if successful
}
}
else
exit = false; // return false if unsuccessful
return exit;
}
void LinkedList::deleteAllNodes()
{
Node *temp;
while ( head.headPtr )
{
temp = head.headPtr;
head.headPtr = head.headPtr -> next;
delete temp;
head.count--;
}
return;
}
bool LinkedList::isEmpty()
{
return head.count == 0;
}
int LinkedList::getNoOfNodes()
{
return head.count;
}
void LinkedList::displayAllNodes()
{
Node *pCur = head.headPtr;
int nodeCount = 1;
while ( pCur )
{
cout << "Node " << nodeCount << ": ";
displayNode( pCur );
cout << endl;
nodeCount++;
pCur = pCur -> next;
}
return;
}
int LinkedList::dataCmp( int value0, int value1 )
{
int exit = 0;
if ( value0 < value1 )
exit = -1;
else if ( value0 > value1 )
exit = 1;
return exit;
}
void LinkedList::displayNode( Node *node )
{
cout << node -> data;
return;
}
void printMenu()
{
cout << "1. Add to head" << endl;
cout << "2. Remove from head" << endl;
cout << "3. Add node " << endl;
cout << "4. Delete node" << endl;
cout << "5. Delete all nodes" << endl;
cout << "6. Is the list empty?" << endl;
cout << "7. Get number of nodes" << endl;
cout << "8. Display all nodes" << endl;
cout << "9. Quit" << endl;
}
int getChoice()
{
int choice;
cout << "Select choice: ";
cin >> choice;
cin.clear();
cin.ignore( 200, '\n' );
return choice;
}
int getData()
{
int data;
cout << "Enter data: ";
cin >> data;
cin.clear();
cin.ignore( 200, '\n' );
return data;
}
void processChoice( int choice, LinkedList& list )
{
int data;
bool opStatus;
switch ( choice )
{
case 1: data = getData();
list.addToHead( data );
break;
case 2: if ( list.removeFromHead() )
{
cout << "Removed node from head" << endl;
}
else
cerr << "List is empty" << endl;
break;
case 3: data = getData();
list.addNode( data );
cout << "Node " << data
<< " added";
cout << endl;
break;
case 4: if ( !list.isEmpty() )
{
data = getData();
if ( list.deleteNode( data ) )
{
cout << "Node " << data
<< " deleted";
cout << endl;
}
else
cerr << "Node not found" << endl;
}
else
cerr << "List is empty" << endl;
break;
case 5: list.deleteAllNodes();
cout << "All nodes deleted" << endl;
break;
case 6: cout << ( list.isEmpty() ?
"List is empty" : "List is not empty" );
cout << endl;
break;
case 7: cout << "No. of nodes: "
<< list.getNoOfNodes();
cout << endl;
break;
case 8: list.displayAllNodes();
break;
default: cout << "Invalid choice" << endl;
}
}
int main()
{
LinkedList list;
int choice;
do
{
printMenu();
choice = getChoice();
if ( choice != 9 )
processChoice( choice, list );
} while ( choice != 9 );
return 0;
}
我觉得“删除节点”选项太模糊了，想把它分成两个功能，按节点号删除（EX：删除节点号0）和按节点号删除（EX：删除节点与5667）。我该怎么做呢？