C++ 单链表

Posted 2021-05-10 Python可视化编程机器学习OpenCV

C++ 实现单链表（类似python的list类型）。

涉及到的基础知识点有：

• 结构体（指针做结构元素）

• 类 （构造函数、拷贝构造函数）

• 指针和引用

• 链表的相关概念

目前我实现的功能有：链表的打印，尾部添加数据，中间任意位置插入数据，删除指定位置的数据 和 查找数据。源码如下：

#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;}