C++ 单链表操作总结

第一、单链表的定义和操作

#include <iostream>
using namespace std;

template <typename T>
struct Node {
    T data;
    Node* next;
};

template <typename T> class SingleLinkList {
public:
    SingleLinkList() {
        head = new Node<T>();
        head->next = NULL;
    }

    ~SingleLinkList() {
        Node<T> *p;
        while (head) {
            p = head;
            head = head->next;
            delete p;
        }
        head = NULL;
    }

    void createLinkList(int n) {

        std::cout << "you create single linklist with "<<n<<" node" << std::endl;
        Node<T>* s, *p;
        p = head;

        for (int i = 0; i < n; i++)
        {           
            s = new Node<T>();
            cout << "please enter the " << i << " number" << endl;
            std::cin >> s->data;
            s->next = NULL;

            p->next = s;
            p = s;
        }
    }

    bool insertNode(T data) {
        Node<T>* p = head;
        while (p->next!=NULL)
        {
            p = p->next;
        }
        
        Node<T> *n = new Node<T>();
        n->data = data;
        n->next = NULL;

        p->next = n;
        return true;
    }

    bool insertNode(int i, T data) {
        Node<T>* p = head;
        int j;
        for (j = 1; j <= i-1; j++)
        {
            p = p->next;
            if (p==NULL)
            {
                break;
            }
        }
        if (p==NULL&&j<(i-1))
        {
            std::cout << "The index:"<<i<<" is not found" << std::endl;
            return false;
        }

        Node<T>* node = new Node<T>();
        node->data = data;
        
        node->next = p->next;
        p->next = node;
        return true;
    }

    bool deleteNode(int i) {
        Node<T>*f = head;
        Node<T>*s = head;
        int j;
        for (j=1; j <= i; j++)
        {
            s = f;
            f = f->next;   
            if (f==NULL)
            {
                break;
            }
        }
        if (j<i+1)
        {
            std::cout << "The index:" << i << " is not found" << std::endl;
            return false;
        }

        s->next = f->next;
        delete f;
        return true;
    }

    T getElement(int i) {
        Node<T> *p = head;
        int j;
        for (j = 1; j <= i; j++)
        {
            p = p->next;
            if (p==NULL)
            {
                break;
            }
        }
        if (j<i && p==NULL)
        {
            std::cout << "The index:" << i << " is not found" << std::endl;
        }

        return p->data;     
    }

    int findNode(T value) {
        Node<T> *p = head;
        int i = 0;
        while (p!=NULL)
        {
            if (p->data==value)
            {
                break;
            }
            p = p->next;
            i++;
        }
        if (p==NULL)
        {
            return -1;
        }
        return i;
    }

    void printAll() {
        Node<T>*p = head->next;
        while (p!=NULL)
        {
            std::cout << p->data << " ";
            p = p->next;           
        }
        cout << endl;
    }

    int lenght() {
        Node<T>*p = head->next;
        int j = 0;
        while (p!=NULL)
        {
            p = p->next;
            j++;
        }
        return j;
    }

    bool clearLink() {     
        Node<T>* current = head->next;
        while (head->next!=NULL)
        {         
            current = head->next;
            head->next = current->next;
            delete current;
        }
        return true;
    }

    bool isEmpty() {
        return head->next == NULL;
    }
private:
    Node<T>* head;
};

　　

第二、控制台演示

#include "pch.h"
#include <iostream>
#include "SingleLinkList.h"
using namespace std;

int main()
{
    SingleLinkList<int> sLinkList;
    cout << "1:createLinkList(int n);" << endl;
    cout << "2:insertNode(T data);" << endl;
    cout << "3:insertNode(int i, T data);" << endl;
    cout << "4:int findNode(T value)" << endl;
    cout << "5:int printAll()" << endl;
    cout << "6:deleteNode(int i)" << endl;
    cout << "7: T getElement(int i)" << endl;
    cout << "8: clearLink()" << endl;
    
    cout << "10:exit;" << endl;
    int cmd=0;
    do {
        cout << "please tap cmd" << endl;
        cin >> cmd;
        switch (cmd)
        {
        case 1:
        {
            cout << "please enter the number of nodes you want to create" << endl;
        int nNum = 0;
        cin >> nNum;
        sLinkList.createLinkList(nNum); 
        }
        break;
        case 2:
            cout << "please enter data " << endl;
            int data;
            cin >> data;
            sLinkList.insertNode(data);
            break;
        case 3:
            cout << "please enter index and data,example 4 10" << endl;
            int d, i;
            cin >> i >> d;
            sLinkList.insertNode(i, d);
            break;
        case 4:
          { cout << "please enter data you want to search" << endl;
        int searchData;
        cin >> searchData;
        int index = sLinkList.findNode(searchData);
        cout << "search index:" << index << endl; }
            break;
        case 5:
            sLinkList.printAll();
            break;
        case 6:
            cout << "please enter index you want to delete" << endl;
            int delIndex;
            cin >> delIndex;
            sLinkList.deleteNode(delIndex);
            break;
        case 7:
            cout << "please enter index" << endl;
            int getIndex;
            cin >> getIndex;
            { int dataElement = sLinkList.getElement(getIndex);
            cout << "value:" << dataElement << endl; }
            break;
        case 8:
            sLinkList.clearLink();
            break;
        default:
            break;
        }
    } while (cmd != 10);

    return 0;
}