循环链表的插入和删除

循环链表可以用来使计算机处理内存工作区或输出至数据缓冲区。

《循环链表的插入和删除》《循环链表的插入和删除》循环链表的插入和删除

   
    
    #include
    "
    iostream
    "
    
#include
" stdlib.h "
using namespace std;

struct clist
{
int data;
struct clist * next;
};
typedef
struct clist cnode;
typedef cnode
* clink;

/* -----循环链表的输出------ */

void printclist( clink head)
{
clink ptr;
head
= head -> next;
ptr
= head;
do
{
printf(
" [%d] " ,ptr -> data);
ptr
= ptr -> next;
}
while (head != ptr && head != head -> next);
printf(
" \n " );

}
/* -----循环链表的结点插入---- */

clink insertnode(clink head,clink ptr,
int value)
{
clink new_node;
new_node
= (clink) malloc( sizeof (cnode));
if ( ! new_node)
return NULL;
new_node
-> data = value;
new_node
-> next = NULL;

if (head == NULL)
{
new_node
-> next = new_node;
return new_node;
}
if (ptr == NULL)
{
/* ----情况1:插在第一结点之前--- */
new_node
-> next = head -> next;
head
-> next -> next = new_node;
}
else
{
/* -----情况2:插在结点之后------- */
new_node
-> next = ptr -> next;
ptr
-> next = new_node;
}
if (ptr == head)
head
= new_node;
return head;
}
/* ---循环链表结点删除--- */
clink deletenode(clink head,clink ptr)
{
clink previous;
if (head == NULL)
{
/* ----情况1:删除第一个结点---- */
head
-> next = ptr -> next;
}
else
{
/* --情况2:删除中间结点--- */
previous
= head;
if (head != head -> next)
while (previous -> next != ptr)
previous
= previous -> next;
previous
-> next = ptr -> next;
}
if (ptr == head)
head
= previous;
free(ptr);
return head;
}

/* 使用插入结点的方式来创建链表,完成后将链表内容输出,然后删除前后两结点 */

int main()
{
clink head
= NULL;
int list[ 6 ] = { 9 , 7 , 3 , 4 , 5 , 6 };
int i;

head
= insertnode(head,head,list[ 0 ]);
printf(
" 创建第一个结点: " );
printclist(head);
/* ---情况1:插在第一结点前---- */
head
= insertnode(head,NULL,list[ 1 ]);
printf(
" 插入第一结点之前: " );
printclist(head);
for (i = 2 ;i < 6 ;i ++ )
{
/* ---情况2:插在结点之后----- */
head
= insertnode(head,head -> next,list[i]);
printf(
" 插入结点之后: " );
printclist(head);
}
/* ---情况1:删除第一个结点--- */
head
= deletenode(head,head -> next);
printf(
" 删除第一个结点: " );
printclist(head);
/* --删除最后一个结点-- */
printf(
" 删除最后一个结点: " );
head
= deletenode(head,head);
printclist(head);
}

 

    原文作者:FC WORLD!!!
    原文地址: https://www.cnblogs.com/FCWORLD/archive/2010/11/20/1882463.html
    本文转自网络文章,转载此文章仅为分享知识,如有侵权,请联系博主进行删除。
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