单链表的基本操作

#include <stdio.h>

#include <stdlib.h>

typedef struct node

{

int data;

struct node * next;

}node;

node *creat()  //创建单链表

{ 

node *head;//头结点 

node *cur;//当前结点 

node *temp;//临时结点 

int x;//数据 

int cycle = 1; 

head = (node*)malloc(sizeof(node));//为头结点分配内存 

head->next = NULL; //初始head->next为空 

cur = head; 

while(cycle) 

{   

printf("please input a data(end to 0):\n"); 

scanf("%d",&x);

if(x!=0) 

{     

temp = (node*)malloc(sizeof(node));     

temp->data = x;   

temp->next = cur->next;//尾结点置空     

cur->next = temp;     

cur=temp; 

} 

else 

{  

cycle = 0;

} 

}

  return head; 

}

int length(node *head)//单链表长度

{

int n = 0; 

node *cur; 

cur = head;   

while ((cur->next)!=NULL) 

{     

cur=cur->next;  

n++; 

}   

return n;

}

void print(node *head)//单链表的打印

{  

node *cur;  

int n = length(head);

  if(head==NULL||head->next==NULL)  

{   

printf("There is no data!\n");   

return;  

}  

printf("These %d datas are:\n",n);

cur=head->next;  

while(cur!=NULL)  

{     

printf("%d   ",cur->data);  

cur=cur->next;  

}  

printf("\n");

}

node * del(node *head,int num)//单链表的删除

{ 

node *cur;

node *per; 

cur = head->next;//当前结点

per = head;//当前结点的前结点   

if(head==NULL||head->next==NULL)//头结点为空或者头结点后无结点 直接返回 

{  

return head;

}

while(num!=(cur->data)&&(cur->next)!=NULL) 

{  

per=cur;  

cur = cur->next;

}

if (num==(cur->data)) 

{ 

per->next = cur->next; 

free(cur); 

}

return head;

}

node *sort(node *head)//单链表的排序

{ 

node *cur; 

int n = length(head); 

int temp;

if(head==NULL||head->next==NULL)//头结点为空或者头结点后无结点 直接返回

{ 

return head; 

}

bool exchanged;

for (int i = 0;i<n-1;i++)//冒泡排序

{ 

exchanged = false;  

cur = head->next; //当前结点  

for(int j = 0;j<n-1-i;j++)  

{  

if ((cur->data) > (cur->next->data))  

{             

temp = cur->data;    

cur->data = cur->next->data;    

cur->next->data = temp;    

exchanged = true;   

}  

cur = cur->next;  //向下移动一个结点  

} 

if (!exchanged) 

{   

return head;

  }    

} 

return head;

}

node *insert(node *head,int num)//单链表的插入
{
node *cur;
node *per;
cur = head->next;
per = head ;
if(head==NULL||head->next==NULL)//头结点为空或者头结点后无结点 直接返回
{
  return head;
}
node *temp = (node*)malloc(sizeof(node));
temp->data = num;
while((temp->data)>(cur->data)&&(cur->next!=NULL))
{
  per = cur;
  cur = cur->next;
}

if ((temp->data) <= (cur->data))//中间插入
{
      temp->next = cur;
   per->next = temp;
}
else  //比链表里的所以数据都大  插到尾结点后
 {
   temp->next = cur->next;
   cur->next = temp;
 }

return head;
}

node * reverse(node *head)

{

node *per,*cur,*temp;

if(head==NULL||head->next==NULL)//头结点为空或者头结点后无结点 直接返回

{  

return head;

}

per = NULL;//前一个结点

cur = head->next;//当前结点

while(cur)

{     

temp = cur->next;//临时结点保存下一个结点指针  

cur->next = per;//当前结点的next指针改为指向前一个结点  

per = cur;//前一个结点向后移动  

cur = temp;//当前结点向后移动

} 

head->next = per;//头结点的next指向最后一个结点  此时cur==NULL 

return head;

}

void RemoveHead(node *head)//删除头元素

{ 

node *temp = head->next;

head->next = temp->next;

  free(temp);

}

 

int main(int argc, char* argv[])

{

int x; 

node * head = creat();

print(head);

printf("the length of the link:%d\n",length(head));

printf("oder the link:\n"); 

sort(head); 

print(head);

printf("please input the data you want to delete:\n");

scanf("%d",&x); 

del(head,x); 

print(head);

printf("please input the data you want to insert:\n");

scanf("%d",&x);

insert(head,x);

print(head);

printf("reverse the link:\n");

reverse(head);

print(head);

RemoveHead(head);
print(head);

return 0;

 

}