c++初级 之 双向链表

以下为例

DoubleLink.h

struct DLNode{int data;DLNode * last;DLNode * next;};class DoubleLink{public:DoubleLink();void insertNode(int position,int data);//在位置m（从0开始）插入新节点（注意位置0和最后一个位置的两个节点是连一起的）void deleteNode(int position);void travel(bool zf,int position,int n);//zf=0正向输出，否则反向输出。从position位置开始输出，（循环）输出n个数int getData(int position);private:DLNode * m_pHead;int m_iLength;};

DoubleLink.cpp

#include"DoubleLink.h"#include<iostream>#include<stdlib.h>using namespace std;DoubleLink::DoubleLink(){m_pHead = new DLNode;m_pHead->last = NULL;m_pHead->next = NULL;m_iLength = 0;cout << "DoubleLink()" << endl;}void DoubleLink::insertNode(int position,int data){DLNode * node = new DLNode;node->data = data;if(m_iLength == 0){m_pHead->next = node;node->last = node;   //是一个头尾相连循环的链表，当只有一个节点时，该节点的前后指向都是节点自身node-> next = node;m_iLength++;}else{if(position == 0){node->next = m_pHead->next;node->last = m_pHead->next->last;m_pHead->next->last->next = node;m_pHead->next->last = node;m_pHead->next = node;   //0位置和其他位置的区别就在于头指针指向了该位置m_iLength++;}else{DLNode* current = m_pHead->next;for(int i = 0;i < position;i ++){current = current->next;}node->next = current;node->last = current->last;current->last->next = node;current->last = node;m_iLength++;}}}void DoubleLink::deleteNode(int position){if(m_iLength == 0){cout << "链表为空无节点可以删除" << endl;}else{if(m_iLength == 1){delete m_pHead->next;m_pHead->next = NULL;m_iLength--;}else{if(position == 0){m_pHead->next->next->last = m_pHead->next->last;m_pHead->next->last->next = m_pHead->next->next;DLNode*temp = m_pHead->next;m_pHead->next = m_pHead->next->next;delete temp;temp = NULL;m_iLength--;}else{DLNode* deleteNode = m_pHead->next;for(int i = 0;i < position;i++){deleteNode = deleteNode->next;}deleteNode->last->next = deleteNode->next;deleteNode->next->last = deleteNode->last;delete deleteNode;deleteNode = NULL;m_iLength--;}}}}void DoubleLink::travel(bool zf,int position,int n){if(m_iLength == 0){cout << "空链表！" << endl;}else{if(!zf){cout << "正向输出：";DLNode* p = m_pHead->next;for(int i = 0;i < position;i++)p = p->next;for(int i = 0;i < n;i++){cout << p->data << ",";p = p->next;}cout << endl;}else{cout << "反向输出：";DLNode* p = m_pHead->next;for(int i = 0;i < position;i++)p = p->next;for(int i = 0;i < n;i++){cout << p->data << ",";p = p->last;}cout << endl;}}}int DoubleLink::getData(int position){if(m_iLength == 0){cout << "空链表！" << endl;return 9999;}else{DLNode*p = m_pHead->next;for(int i = 0;i < position;i ++){p = p->next;}return p->data;}}

demo.cpp

#include<iostream>#include<stdlib.h>#include"DoubleLink.h"using namespace std;int main(){DoubleLink dl;int data = dl.getData(3);cout << data << endl;dl.deleteNode(5);dl.travel(0,3,10);for(int i = 0;i <6;i++){dl.insertNode(0,i);//5、4、3、2、1、0}data = dl.getData(3);cout << data << endl;dl.deleteNode(0);dl.travel(0,3,10);//从位置3开始正向循环输出10个数据dl.travel(1,3,10);//反向system("pause");return 0;}

运行结果：