单链表常见的面试题，及应用

//编程实现一个单链表的建立/长度/打印
#include<iostream>
#include<cstring>
#include<cstdio>
#include<conio.h>
#include<stdlib.h>
using namespace std;
typedef struct  student
{
    int data;
    struct student *next;
}node;
node *creat()//单链表的建立
{
    node *head,*p,*s;
    int x,cycle=1;
    head=new node;
    p=head;
    while(cycle)
    {
        printf("input the data
");
        scanf("%d",&x);
        if(x!=0)
        {
            s=new node;
            s->data=x;
            p->next=s;
            p=s;
        }
        else
         cycle=0;

    }
    head=head->next;
   p->next=NULL;
   return head;
}
node *del(node *head,int num)//实现单链表删除节点。
{
    node *p,*q;
    p=head;
    while(p->next!=NULL)
    {
       if(p->data==num)
       {
         if(p==head)
         {
             head=p->next;
             free(p);
             return head;
         }
         else
           {
               //printf("p=%d,q=%d
",p->data,q->data);
               q->next=p->next;
           }
       }
        q=p;
       p=p->next;

    }
    return head;
}
node *insert(node *head,int num)
{
      node *p0,*p1,*p2;
      p1=head;
      p0=new node;
      p0->data=num;
      while(p0->data>p1->data&&p1->next!=NULL)
      {
          p2=p1;p1=p1->next;
      }
     // printf("p0=%d,p1=%d,p2=%d
",p0->data,p1->data,p2->data);
      if(p0->data<=p1->data)
      {
          if(head==p1)
             {
                 p0->next=p1;
                 head=p0;
             }
        else
        {
            p2->next=p0;
            p0->next=p1;
        }

    }
     else
      {
         p1->next=p0;
         p0->next=NULL;
      }
      return (head);
}
void print(node *head)//单链表打印
{
       node *p=head;
         p=head;
         while(p!=NULL)
         {
           printf("%d ",p->data);
            p=p->next;
         }
         printf("
");
}
int length(node *head)
{
    int n=0;
    node *p;
    p=head;
    while(p!=NULL)
    {
        p=p->next;
        n++;
    }
    return n;
}
node *sort(node *head)
{
  node *p;

  int n=length(head);
  int i,j,temp;
  if(head==NULL||head->next==NULL)
      return head;
    p=head;
  for(i=0;i<n;i++)
   {
          p=head;//???????
       for(j=i+1;j<n;j++)
       {
          if(p->data>p->next->data)
          {
              temp=p->data;
              p->data=p->next->data;
              p->next->data=temp;
          }
          p=p->next;
       }
   }
   return head;
}
node *reverse(node *head)//单链表的逆置
{
    node *p1,*p2,*p3;
    if(head==NULL||head->next==NULL)
        return head;
    p1=head;
    p2=p1->next;
    while(p2)
    {
        p3=p2->next;
        p2->next=p1;
        p1=p2;
        p2=p3;
    }
    head->next=NULL;
    head=p1;
    return head;
}
int  main()
{
       node *head;
        head=creat();
        printf("创建链表为
");
        print(head);
         int t1,t2;
        printf("请输入删除的数
");
         scanf("%d",&t1);
        head=del(head,t1);
         print(head);
        printf("请输入插入的数
");
         scanf("%d",&t2);
        head= insert(head,t2);
        print(head);
        printf("单链表排序从小到大
");
        head=sort(head);
         print(head);
         printf("链表逆置
");
         head=reverse(head);
         print(head);
         return 0;
}