用C++编写的双向链表程序示例
// \*********** 用C++编写一个双链表的程序***********/ //
/*--------- 本文可以帮助大家快速的学习如何建立双向链表，以及对双向链表进行的相关操作
，比如删除节点、插入节点、链表排序、计算链表长度、打印双向链表等操作--------- */
#include
using namespace std;
//定义双向链表的节点
typedef struct student
{
int data;
struct student *pre;
struct student *next;
}dnode;
//建立双向链表
dnode *creat()
{
int cycle = 1;
int x;
dnode *head, *t, *s=NULL;
head = new dnode;
t = head;
while (cycle)
{
cout << "Please input a 'int' type number: " << endl;
cin >> x;
if (x != 0)
{
s = new dnode;
s->data = x;
t->next = s;
s->pre = t;
t = s;
}
else
cycle = 0;
}
head = head->next;
head->pre = NULL;
t->next = NULL;
cout << "第一个节点的值：" << endl ;
cout << head->data << endl << endl;
return head;
}
//计算双向链表的长度
int length(dnode *head)
{
int n=0;
dnode *p;
p = head;
while (p != NULL)
{
n++;
p = p->next;
}
return n;
}
//打印双向链表并计算链表的长度
int print(dnode *head)
{
int n = 0;
dnode *p;
p = head;
while (p != NULL)
{
n++;
cout << p->data << endl;
p = p->next;
}
cout << "Length= " << n << endl;
return n;
}
//实现双向链表中节点的删除
dnode *del(dnode *head)
{
dnode *p;
int num;
p = new dnode;
p = head;
//输入要删除的节点上的值
cout << "Please input the deletating value:" << endl;
cin >> num;
while (num != p->data && p->next != NULL)
{
p = p->next;
}
if (num == p->data)
{
if (p == head)
{
head = head->next;
head->pre = NULL;
delete(p);
}
else if (p->next == NULL)
{
p->pre->next = NULL;
delete(p);
}
else
{
p->pre->next = p->next;
p->next->pre = p->pre;
}
}
else
{
cout << "Don't find the 'num' :" << endl;
}
return head;
}
//双向链表中插入节点
dnode *insert(dnode *head)
{
dnode *p0, *p;
int num;
p = head;
p0 = new dnode;
cout << "Please input the inserting value:" << endl;
cin >> num;
p0->data = num;
while (p0->data > p->data&&p->next != NULL)
{
p = p->next;
}
if (p0->data <= p->data)
{
if (p == head)
{
head = p0;
p0->pre = NULL;
p0->next = p;
p->pre = p0;
}
else
{
p->pre->next = p0;
p0->pre = p->pre;
p0->next = p;
p->pre = p0;
/*p->next = p0;
p0->pre = p;
p0->next = p->next;
p->next->pre = p0;*/
}
}
else
{
p->next = p0;
p0->pre = p;
p0->next = NULL;
}
return head;
}
//对双向链表进行排序
dnode *sort(dnode *head)
dnode *p;
int t,n;
p = head;
n = length(p);
for (int i = 0; i < n - 1; i++)
{
p = head;
for (int j = 0; j < n - 1 - i; j++)
{
if (p->data > p->next->data)
{
t = p->data;
p->data = p->next->data;
p->next->data = t;
}
p = p->next;
}
}
return head;
}
int main()
{
dnode *head;
head = creat();
cout << "创建的双向链表为：" << endl;
print(head);
cout << "head = " << head << endl << endl;
head=del(head);
cout << "删除节点之后的双向链表为：" << endl;
print(head);
head = insert(head);
cout << "插入节点之后的双向链表为：" << endl;
print(head);
head = sort(head);
cout << "排序之后的双向链表为：" << endl;
print(head);
}
/*备注：在进行链表插入时要注意，链表中的值，
、从头节点向后默认是增加的，所以插入的节点位于两个节点中间时，插入节点的位置应该是在p节点之前。如下图所示：*/
实验验证：
创建链表输入：1 ，2，3，65，12，11，70
删除：12
插入：68
最后按照冒泡排序发进行排序。