数据结构——双向链表的创建、插入、删除

 

#include "iostream"
using namespace std;
typedef struct DuLNode{
	int data;
	struct DuLNode *prior;
	struct DuLNode *next;
}DuLNode,*DuLinkList;
void CreateDuLinkList(DuLinkList&L,int n);
void ShowDuLinkList(DuLinkList&L);
void InsertDuLinkList(DuLinkList&L,int element,int location);
void DeleteDuLinkList(DuLinkList&L,int location,int&element);
void main(){
	DuLinkList L;
	CreateDuLinkList(L,5);
	ShowDuLinkList(L);
	InsertDuLinkList(L,100,3);
	ShowDuLinkList(L);
	int element;
	DeleteDuLinkList(L,3,element);
	ShowDuLinkList(L);
}
void CreateDuLinkList(DuLinkList&L,int n){
	L = (DuLinkList)malloc(sizeof(DuLNode));
	DuLinkList slide = L;
	int len = 0;
	for (int i = 0;i<n;i++)
	{

		DuLinkList p = (DuLinkList)malloc(sizeof(DuLNode));
		p->data = i;
		slide->next = p;
		p->prior = slide;
		slide = p;
		len++;
	}
	slide->next = L;
	L->data = len;//头结点中的数据域保存链表的长度

}
void ShowDuLinkList(DuLinkList&L){
	DuLinkList slide = L->next;
	//头结点中的数据域保存链表的长度,可以采用这种方式
	for (int i = 0;i<L->data;i++)
	{
		cout<<slide->data<<endl;
		slide = slide->next;
	}
	////任意链表均可以采用这种形式
	//while(slide!=L){
	//	cout<<slide->data<<endl;
	//	slide = slide->next;
	//}
	cout<<"---------------------"<<endl;
}
void InsertDuLinkList(DuLinkList&L,int element,int location){
	//扫描定位
	// 1<=location<=len+i
	DuLinkList slide = L;
	int loc = 1;
	while(slide&&loc<=location){
		slide = slide->next;
		loc++;
	}
	if (location>1&&slide!=L)
	{

		DuLinkList p = (DuLinkList)malloc(sizeof(DuLNode));
		p->data = element;
		p->prior = slide->prior;
		slide->prior->next = p;
		slide->prior = p;
		p->next = slide;
	}
}
void DeleteDuLinkList(DuLinkList&L,int location,int&element){
	//扫描定位
	// 1<=location<=len+i
	DuLinkList slide = L;
	int loc = 1;
	while(slide&&loc<=location){
		slide = slide->next;
		loc++;
	}
	if (slide!=L)
	{
		element = slide->data;
		slide->prior->next = slide->next;
		slide->next->prior = slide->prior;
		free(slide);

	}


}