数据结构C三双向链表_三向链表

双链表是给链表中的每一个节点多加一个指针域，这个指针域将指向它的前驱，因此在双链表上，既方便查找后继，又方便查找节点的前驱。抄写并理解代码。

1.双向链表的存储，建立链表。

typedef struct DoubleLinkedNode{
	char data;
	struct DoubleLinkedNode *previous;
	struct DoubleLinkedNode *next;
}DLNode, *DLNodePtr;

2.双向链表初始化

DLNodePtr initLinkList(){
	DLNodePtr tempHeader = (DLNodePtr)malloc(sizeof(struct DoubleLinkedNode));
	tempHeader->data = '\o';
	tempHeader->previous = NULL;
	tempHeader->next = NULL;
	return tempHeader;
}

3.双向链表打印

void printList(DLNodePtr paraHeader){
	DLNodePtr p = paraHeader->next;
	while (p != NULL){
		printf("%c",p->data);
		p = p->next;
	}
	printf("\r\n");
}

4.双向链表按位插入元素

void insertElement(DLNodePtr paraHeader,char paraChar,int paraPosition){
	DLNodePtr p,q,r;
	
	
	p = paraHeader;
	for(int i = 0;i < paraPosition; i ++){
		p = p->next;
		if(p == NULL) {
			printf("The position %d is beyond the scope of the list.",paraPosition);
			return;
		}
	}
	
	
	q = (DLNodePtr)malloc(sizeof(struct DoubleLinkedNode));
	q->data = paraChar;
	
	
	r = p->next;
	q->next = p->next;
	q->previous = p;
	p->next = q;
	if (r != NULL){
		r->previous = q;
	}
}

5.删除指定元素

void deleteElement(DLNodePtr paraHeader, char paraChar){
	DLNodePtr p,q,r;
	p = paraHeader;
	
	
	while((p->next != NULL) && (p->next->data != paraChar)){
		p = p->next;
	}
	
	
	if(p->next == NULL){
		printf("The char'%c' does not exist.\r\n",paraChar);
		return;
	}
	
	
	q = p->next;
	r = q->next;
	p->next = r;
	if(r != NULL) {
		r->previous = p; 
	}
	
	
	free(q);
}

6.插入元素，测试操作

void insertDeleteTest(){
	
	DLNodePtr tempList = initLinkList();
	printList(tempList);
	
	
	insertElement(tempList, 'H',0);
	insertElement(tempList, 'e',1);
	insertElement(tempList, 'l',2);
	insertElement(tempList, 'l',3);
	insertElement(tempList, 'o',4);
	insertElement(tempList, '!',5);
	printList(tempList);
	
	
	deleteElement(tempList, 'e');
	deleteElement(tempList, 'a');
	deleteElement(tempList, 'o');
	printList(tempList);
 
}

7.地址的显示

void basicAddressTest(){
	DLNode tempNode1, tempNode2;
 
	tempNode1.data = 4;
	tempNode1.next = NULL;
 
	tempNode2.data = 6;
	tempNode2.next = NULL;
 
	printf("The first node: %d, %d, %d\r\n",
		&tempNode1, &tempNode1.data, &tempNode1.next);
	printf("The second node: %d, %d, %d\r\n",
		&tempNode2, &tempNode2.data, &tempNode2.next);
 
	tempNode1.next = &tempNode2;
}

8.运行结果

 9.理解图示