对 带头结点的单链表 的操作
//带头结点的单链表
#include<iostream>
using namespace std;
typedef struct student
{
int data;
struct student *next;
}node;
node * creat() //创建单链表
{
node *head,*p,*s;
int x,cycle=1;
head=(node *)malloc(sizeof(node));
p=head;
while(cycle)
{
cout<<"请输入一直不为0的数，输入0则结束"<<endl;
cin>>x;
if(x!=0)
{
s=(node *)malloc(sizeof(node));
s->data=x;
p->next=s;
p=s;
}
else cycle=0;
}
p->next=NULL;
return head;
}
int listLength(node *head) //单链表的测长
{
int i=0;
node *p=head;
p=head;
do
{
p=p->next;
i++;
}while(p->next!=NULL);
return i;
}
void printList(node *head) //打印单链表
{
node *p=head->next;
int len=listLength(head);
for(int i=0;i<len;i++)
{
cout<<p->data<<endl;
p=p->next;
}
}
node * deleteNode(node *head,int e) //删除单链表的结点
{
node *p1,*p2;
p1=head->next;
while(p1->data!=e && p1->next!=NULL)
{
p2=p1;
p1=p1->next;
}
if(e==p1->data)
{
if(p1==head->next)
{
head->next=p1->next;
free(p1);
}
else
{
p2->next=p1->next;
free(p1);
}
}
else
cout<<"未找到结点的数据域值为："<<e<<"的结点"<<endl;
return head;
}
node * insert(node *head,int e) //链表插入一个结点
{
node *p1,*p2,*s;
p1=head->next;
s=(node *)malloc(sizeof(node));
s->data=e;
while(s->data > p1->data && p1->next!=NULL)
{
p2=p1;
p1=p1->next;
}
if(s->data < p1->data)
{
if(p1==head->next)
{
s->next=p1;
head->next=s;
}
else
{
s->next=p1;
p2->next=s;
}
}
else
p1->next=s;
s->next=NULL;
return head;
}
int main()
{
node *head;
head=creat();
printList(head);
head=insert(head,3);
printList(head);
return 0;
}
