删除链接列表上的更多特定节点

Question

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，想把它分为两个功能，按节点号删除（EX：删除节点号0）和按节点号删除。我该怎么做？

Answer 1

要根据节点的值删除节点，您必须遍历列表，并检查每个节点的值是否与您试图从列表中删除的值匹配。

我相信这是你能做到这一点的唯一方法。