单链表类，链表逆置

 1 #pragma once
 2 #include"iostream"
 3 #include <cstdlib>
 4 #include <time.h>
 5 using namespace std;
 6  
 7 struct Node
 8 {
 9     int val;
10     Node *next;
11     Node(int nVal, Node *nNext = NULL) {
12         val = nVal;
13         next = nNext;
14     }
15     Node() {}
16 };
17  
18 class ListNode
19 {
20 private:
21     Node *head;  //声明头节点
22     int counts;
23  
24 public:
25     ListNode();
26     ~ListNode();
27     void CreateList(int n);
28     void CreateListByPC(int n,int randnum);
29     ListNode* Reverse();
30     ListNode* ReverseBetween(int m, int n);
31     void ShowList();
32     int ListLength();
33     void InsertNode(int position, int value);
34     void DeleteNode(int position);
35     Node *GetNodeByPosition(int position);
36 };[/align]
37 [align=center]
38 [size=6][color=#48d1cc]源文件[/color][/size]

实现文件如下：

#include "ListNode.h"
 
 
ListNode::ListNode()
{
    head = new Node;
    head->next = NULL;
    head->val = 0;
}
 
ListNode::~ListNode()
{
    Node * temp = head; //创建一个临时变量保存删除节点信息
    while(head->next){
        temp = head->next;
        delete head;
        head = temp;
    }
    delete head;
    cout << "该链表析构完成..." << endl;
}
 
void ListNode::CreateList(int n)
{
    cout << "正在创建长度为" << n << "的链表......" << endl;
    Node *preNode = head;
    for (int i = 0; i < n; i++)
    {
        Node *newNode = new Node;
        cout << "请输入该节点的值: ";
        cin >> newNode->val;
        newNode->next = NULL;
        preNode->next = newNode;
        preNode = newNode;
    }
}
 
void ListNode::CreateListByPC(int n, int randnum)
{
    cout << "正在创建长度为" << n << "的链表，其值范围为:" << randnum << endl;
    srand((unsigned int)time(NULL));
    Node *preNode = head;
    for (int i = 0; i < n; i++)
    {
        Node *newNode = new Node;
        newNode->val = rand()%randnum;
        newNode->next = NULL;
        preNode->next = newNode;
        preNode = newNode;
    }
}
 
ListNode * ListNode::Reverse()
{
    cout << "正在逆置链表..." << endl;
    Node *newHead = NULL;           //临时变量，遍历新链表
    Node *vNode = head->next;        //取第一个节点开始遍历
    while (vNode!=NULL)
    {
        Node *temp = vNode->next;    //备份原链表的下一个节点信息
        vNode->next = newHead;       //当前节点的指针域修改
        newHead = vNode;
        vNode = temp;
    }
    head->next = newHead;
    return NULL;
}
 
ListNode * ListNode::ReverseBetween(int m,int n)
{
    if (m <= 0 || n >= this->counts)
        return false;
    Node *temp = head;              //临时变量保存头节点
    int changeLength = n - m + 1;   //获取需要逆置的个数
 
    while (--m)
    {
        temp = temp->next;
    }
 
    Node *preNode = temp;       //找到m节点的前置节点
    temp = temp->next;
    Node *changeTail = temp;    //m节点,即需要改变的尾节点
    Node *newHead = NULL;
     
 
    cout << "changeLength = " << changeLength << endl;
 
    int i = 0;
    while (changeLength--)
    {
        cout << "正在执行第" << ++i << "ci" << endl;
        Node *vNode = temp->next;    //备份下一个节点的信息
        temp->next = newHead;
        newHead = temp;
        temp = vNode;
    }
 
    preNode->next = newHead;
    changeTail->next = temp;
    return NULL;
}
 
void ListNode::ShowList()
{
    Node *tempNode = head;
    while (tempNode->next)
    {
        cout << tempNode->next->val <<"\t";
        tempNode = tempNode->next;
    }
    cout << endl << "该链表已显示完毕..." << endl;
}
 
int ListNode::ListLength()
{
    Node *temp = head;
    for (; temp->next != NULL; temp = temp->next)
        counts++;
    return counts;
}
 
void ListNode::InsertNode(int position, int value)
{
    Node *temp = this->GetNodeByPosition(position - 1);
    Node *newNode = new Node(value);
    newNode->next = temp->next;
    temp->next = newNode;
}
 
void ListNode::DeleteNode(int position)
{
    if (position<1 || position>this->ListLength())
        return;
    Node *temp = this->GetNodeByPosition(position - 1);
    Node *delNode = temp->next;
    temp->next = delNode->next;
    delete delNode;
}
 
Node * ListNode::GetNodeByPosition(int position)
{
    if (position<1 || position>this->ListLength())
        return flase;
 
    Node *temp = head;
    for (int i = 0; i < position; i++)
        temp = temp->next;
    return temp;
}