单链表结构

#include <stdio.h>
#include <stdlib.h>

typedef struct Student
{
int data;
struct Student* next;
}node;

node* CreateLink(node* head)
{
node* p = NULL;
node* s = NULL;
head = p;
int cycle = 1;
int x = 0;

while(cycle != 0)
{
scanf_s( "%d", &x);
if(x != 0)
{
s = (node*)malloc(sizeof(node));
s->data = x;
if( NULL == head)
{
p = s;
head = p;
}
else
{
p-> next = s;
p = s;
}
}
else
{
cycle = 0;
}
}
p-> next = NULL;
return head;
}

int LenLink(node* const head)
{
node* p = head;
int n = 0;

if(p == NULL)
{
printf( "This is a empty link.\n");
return 0;
}
while(p-> next != NULL)
{
n++;
p = p-> next;
}
return n+1;
}

void Print(node* const head)
{
node* p = head;
if(p == NULL)
{
printf( "This is a empty link.\n");
return;
}
while(p-> next != NULL)
{
printf( "%d\n", p->data);
p = p-> next;
}
printf( "%d\n", p->data);
}
node*DelNode(node* head, int var)
{
node* p = head;
node* s = p;
if( NULL == head)
{
printf( "This is a empty link.\n");
return head = NULL;
}
else
{
while(p-> next != NULL)
{
if(p->data == var)
{
if(p == head)
{
head = p-> next;
free(p);
p = head;
s = p;
}
else
{
s-> next = p-> next;
free(p);
p = s-> next;
}
}
else
{
s = p;
p = p-> next;
}
}
if(p == head && p->data == var)
{
free(p);
return head = NULL;
}
else
{
if(p->data == var)
{
s-> next = NULL;
free(p);
p = NULL;
}
}
}
return head;
}

node* InsNode(node* head, int i)
{
node* p1 = head;
node* p2 = head;
node* s = (node*)malloc(sizeof(node));
s->data = i;

if( NULL == head)
{
printf( "This is a empty link.\n");
head = s;
return head;
}
else
{
while(s->data > p1->data && p1 != NULL)
{
p2 = p1;
p1 = p1-> next;
}
if(s->data <= p1->data)
{
if(head == p1)
{
head = s;
s-> next = p1;
}
else
{
p2-> next = s;
s-> next = p1;
}
}
else
{
p1-> next = s;
s-> next = NULL;
}
}
return head;
}

node* RevLink(node* head)
{
node* p1 = head;
node* p2 = head;
node* p3 = head;

if( NULL == head || NULL == head-> next)
{
return head;
}
else
{
p2 = p1-> next;
while(p2)
{
p3 = p2-> next;
p2-> next = p1;
p1 = p2;
p2 = p3;
}
head-> next = NULL;
head = p1;
return head;
}
}

void Release(node* head)
{
node* p = head;

if( NULL == head)
{
printf( "This is a empty link.\n");
return;
}

while(p-> next != NULL)
{
head = p-> next;
free(p);
p = head;
}
free(head);
}

int main(int argc, char* argv[])
{
node* head = NULL;
//创建单链表
head = CreateLink(head);
//打印链表长度
printf( "Length of single link: %d\n", LenLink(head));
//打印链表
Print(head);
head = DelNode(head, 5);
//打印链表长度
printf( "Length of single link after delete node: %d\n", LenLink(head));
//打印链表
Print(head);
head = InsNode(head, 5);
//打印链表长度
printf( "Length of single link after insert node: %d\n", LenLink(head));
//打印链表
Print(head);
head = RevLink(head);
//打印链表长度
printf( "Length of single link after reverse: %d\n", LenLink(head));
//打印链表
Print(head);
//释放链表堆空间
Release(head);
return 0;
}