C++ 单链表

#include <iostream>
using namespace std;


struct Node //结构体做节点
{
    //每个节点包含一个数据（可以改成复合类型的数据）和指向下一个节点的指针
    float v;
    struct Node *p;
};


class List
{
private:
    struct Node *headP; //指向头节点的指针
    struct Node *tailP; //指向尾巴节点的指针
public:
    int length;
    
    List()
    {
        cout<< "List无参构造函数调用"<< endl;
        headP = NULL;
        tailP = NULL;
        length = 0;
    };
    
    List(List& source)
    {
        cout<< "List 拷贝函数调用"<<endl;
        if(source.headP==NULL)
        {
            this->headP = NULL;
            this->tailP = NULL;
            this->length = 0;
            return;
        }
        //创建新节点指针数组
        struct Node *NP[source.length];
        for(int i =0; i < source.length; i++)
        {
            NP[i] = new struct Node;
        }
        this->headP = NP[0];
        struct Node sourceNode = *(source.headP);
        int i;
        for(i =0; i< source.length-1; i++)
        {
            (*NP[i]).v = sourceNode.v;
            (*NP[i]).p = NP[i+1];
            sourceNode = *(sourceNode.p);
        }
        (*NP[i]).v = sourceNode.v;
        (*NP[i]).p = NULL;
        tailP = NP[i];
        this->length = source.length;
    }
    
    //~List()
    //{
    //    cout<< "List析构函数调用"<< endl;
    //};
    
    List & append(float value)//添加元素
{
        //创建新节点指针
        struct Node *newP = new struct Node;
        *newP ={value, NULL};
        if(this->length == 0)
        {
            headP = newP;
        }
        else
        {
            (*tailP).p = newP;
        }
        tailP = newP;
        this->length ++;
        return *this;
    }
    
    List & insert(int index, float value)//插入元素
{
        if(index > this->length)
        {
            cout <<"Error, the index is out of range, ignored!" << endl;
            return *this;
        }
        if(index == this->length)
        {
            this->append(value);
            return *this;
        }
        //创建新节点指针
        struct Node *newP = new struct Node;
        *newP ={value, NULL};
        struct Node * nodeP = this->headP;
        if(index == 0)
        {
            (*newP).p = this->headP;
            this->headP = newP;
            this->length ++;
            return *this;
        }
        for(int i =0; i<index-1; i++)
        {
            nodeP = (*nodeP).p;
        }
        (*newP).p = (*nodeP).p;
        (*nodeP).p = newP;
        this->length ++;
        return *this;
    }
    
    float pop(int index)//弹出指定位置元素
  {
        if(index >= this->length || index <0 )
        {
            cout <<"Error, the index is out of range, ignored! ";
            return -1.0f;
        }
        struct Node * nodeP = this->headP;
        struct Node * pop_nodeP, *next_nodeP;
        if(index == 0)
        {
            float value = (*nodeP).v;
            nodeP = (*nodeP).p;
            this->headP = nodeP;
            this->length --;
            return value;
        }
        for(int i =0; i<index-1; i++)
        {
            nodeP = (*nodeP).p;
        }
        pop_nodeP = (*nodeP).p;
        next_nodeP = (*pop_nodeP).p;
        (*nodeP).p = next_nodeP;
        this->length --;
        //cout<<this->tailP->v<<endl;
        return (*pop_nodeP).v;
    }
  
    int index(float value, float precision = 1.0e-10)//查找元素
{
        //查找给定值第一次出现的位置
        //-1 代表找不到
        if(this->headP == NULL)
        {
            cout <<"NULL"<<endl;
            return -1;
        }
        struct Node node = *(this->headP);
        int i = 0;
        while(node.p)
        {
            float delta = node.v -value;
            if(delta >= -precision and delta <= precision)//因浮点数精度问题，这里改成范围
            {
                return i;
            }
            node = *(node.p);
            i++;
        }
            float delta = node.v -value;
            if(delta >= -precision and delta <= precision)//因浮点数精度问题，这里改成范围
            {
                return i;
            }
            return -1;
    }
   
    void print()//完全打印链表结果（含指针和数据）
{
        if(this->headP == NULL)
        {
            cout <<"NULL"<<endl;
            return;
        }
        struct Node node = *(this->headP);
        cout<<this->headP<<"(head)-->";
        while(node.p)
        {
            cout<<node.v<<","<<node.p<<"-->";
            node = *(node.p);
        }
        cout<<node.v<<", "<<node.p<<"--|"<<endl;//尾巴节点
        //cout<<(*(this->tailP)).v<<";"<<(*(this->tailP)).p<<endl;
    }
    
    void print_PyStyle()//python风格打印链表结果（仅含数据）
{
        if(this->headP == NULL)
        {
            cout <<"[]"<<endl;
            return;
        }
        struct Node node = *(this->headP);
        cout<<"[";
        while(node.p)
        {
            cout<<node.v<<",";
            node = *(node.p);
        }
        cout<<node.v<<"]"<<endl;//尾巴节点
    }
};


int main()
{
    //测试
    List l1 ;
    l1.append(1.0f).append(2.0f).append(3.0f).append(99.f);
    //l1.print();
    l1.print_PyStyle();
    cout<< l1.length<<endl;
    List l2 = l1;
    l2.print();
    l2.print_PyStyle();
    cout<< l2.length<<endl;
    l2.insert(2,88);
    l2.insert(1,7);
    cout<< l2.length<<endl;
    l2.insert(7,66);
    l2.print();
    l2.print_PyStyle();
    cout<<"pop:"<<l2.pop(2)<<endl;
    l2.print_PyStyle();
    cout<<"pop:"<<l2.pop(0)<<endl;
    l2.print_PyStyle();
    cout<<"pop:"<<l2.pop(3)<<endl;
    l2.print_PyStyle();
    cout<<"pop:"<<l2.pop(2)<<endl;
    l2.print_PyStyle();
    cout<<"pop:"<<l2.pop(1)<<endl;
    l2.print_PyStyle();
    cout<<"pop:"<<l2.pop(0)<<endl;
    l2.print_PyStyle();
    cout<<"pop:"<<l2.pop(0)<<endl;
    l2.print_PyStyle();
    cout<<"l2 length: "<<l2.length<<endl;
    cout<<"l1 length: "<<l1.length<<endl;;
    l2.insert(0,555.0f);
    l2.append(1).append(2).append(3);
    l2.print_PyStyle();
    cout<<"index= "<<l2.index(3.0)<<endl;
    cout<<"index= "<<l2.index(2.8)<<endl;
    return 0;
}