C++ 单链表创建、插入和删除

#include <iostream>
#include <stdio.h>
#include <string>
#include <conio.h>

/**
* cstdio是将stdio.h的内容用C++头文件的形式表示出来。
*stdio.h是C标准函数库中的头文件，即：standard buffered input&output。
*提供基本的文字的输入输出流操作（包括屏幕和文件等）。                                                                   
*/

/**
*conio是Console Input/Output（控制台输入输出）的简写，其中定义了通过控制台进行数据输入和数据输出的函数，
*主要是一些用户通过按键盘产生的对应操作，比如getch()()函数等等。                                                       
*/

using namespace std;

struct node
{
  int data;
  node *next;
};
// 创建单链表
node *creat()
{
  node *head, *p;
  head = new node;
  p = head;
  
  int x, cycle = 1;
  while (cycle)
  {
    cout << "Please input the data for single linker : ";
    cin >> x;

    if (x != 0)
    {
      node *s = new node;
      s->data = x;
      cout << "Input data : " << x << endl;

      p->next = s;
      p = s;
    } 
    else
    {
      cycle = 0;
      cout << "Input done! " << endl;
    }
  }

  head = head->next;
  p->next = NULL;
  //cout << "\nFirst data of single linker is " << head->data << endl;
  
  return head;
}

// 单链表测长
int length(node *head)
{
  int n   = 0;
  node *p = head;

  while (p != NULL)
  {
    p = p->next;
    n++;
  }

  return n;
}

// 单链表打印
void printL(node *head)
{
  node *p = head;

  while(p != NULL)
  {
    cout << "Single Linker data is " << p->data << endl;
    p = p->next;
  }
}

// 单链表插入
node *insert(node *head, int num)
{
  node *p0, *p1, *p2;
  p1 = head;

  p2 = new node;
  p0 = new node; // 插入节点
  p0->data = num;// 插入数据

  while (p0->data > p1->data && p1->next != NULL)
  {
    p2 = p1;
    p1 = p1->next;// p0,p1和p2位置: p2->p1->p0
  }

  if (p0->data <= p1->data)
  {
    if (p1 == head)
    {// 头部前段插入 p0和p1位置: p0->p1->...
      head = p0;
      p0->next = p1;    
    } 
    else
    {// 插入中间节点 p0,p1和p2位置: p2-> p0 -> p1
      p2->next = p0;
      p0->next = p1;
    }
  } 
  else
  {   // 尾部插入节点 p0,p1和p2位置: p2->p1->p0->NULL
    p1->next = p0;
    p0->next = NULL;
  }
  return head;
}

// 单链表删除
node *del(node *head, int num)
{
  node *p1, *p2;
  p2 = new node;
  p1 = head;

  while (num != p1->data && p1->next != NULL)
  {
    p2 = p1;
    p1 = p1->next;// p1和p2位置: p2->p1   
  }

  if (num == p1->data)
  {
    if (p1 == head)// 删除头节点
    {
      head = p1->next;
      delete p1;
    } 
    else
    {
      p2->next = p1->next;
      delete p1;
    }
  } 
  else
  {
    cout << num << " could not been found in the current single linker!" << endl;
  }
  return head;
}


int main()
{
  cout << "***创建单链表***" << endl;
  node *head = creat();
  cout << endl;

  cout << "***计算链表长***" << endl;
  int n = length(head);
  cout << "The length of input single linker is " << n << "." << endl;
  cout << endl;

  cout << "***打印单链表***" << endl;
  printL(head);
  cout << endl;

  cout << "****插入节点****" << endl;
  cout << "Please input the data for inserting operate : ";
  int inData;
  cin >> inData;
  head = insert(head,inData);
  printL(head);
  cout << endl;

  cout << "****删除节点****" << endl;
  cout << "Please input the data for deleting operate : ";
  int outData;
  cin >> outData;
  head = del(head, outData);
  printL(head);
  cout << endl;

  return 0;
}

1.头节点插入和删除结果

2.中间节点插入和删除结果

3.尾结点插入和删除结果