浅学C++(5)数据结构与算法(循环链表)

封装链表：
    尾添加的效率低、非法下标的判断效率也非常低
    1，单链表
        节点：数据域+指针域
        单链表的数据项：
            头节带
            尾节点
            节点数量

#include 
#include 
#include 

#define TYPE int

//封装了带头节点的单链表

typedef struct Node
{
	TYPE date;
	struct Node* next;
}Node;


Node* create_node(TYPE val)
{
	Node* node = malloc(sizeof(Node));
	node->date = val;
	node->next = NULL;
	return node;
}

//封装单链表结构
typedef struct List
{
	Node* head;//头指针
	Node* tail;//尾指针
	size_t size;//节点数量
}List;

//创建单链表
List* create_list(void)
{
	List* list = malloc(sizeof(List));
	list->head = create_node(0);//带头节点的链表
	list->tail = NULL;
	list->size = 0;
}

//头添加
void add_head_list(List* list,TYPE val)
{
	Node* node = create_node(val);
	if(0 == list->size)
	{
		list->head->next = node;
		list->tail = node;
	}
	else
	{
		node->next = list->head->next;
		list->head->next = node;
	}
	list->size++;
}

//尾添加
void add_tail_list(List* list,TYPE val)
{
	Node* node = create_node(val);
	if(0 == list->size)
	{
		list->head->next = node;
		list->tail = node;
	}
	else
	{
		list->tail->next = node;
		list->tail = node;
	}
	list->size++;
}

//头删除
bool del_head_list(List* list)
{
	if(0 == list->size) return false;
	Node* temp = list->head->next;
	list->head->next = temp->next;
	if(1 == list->size) list->tail = NULL;
	list->size--;
	free(temp);
	return true;
}

//尾删除
bool del_tail_list(List* list)
{
	if(0 == list->size) return false;
	free(list->tail);
	if(1 == list->size)
	{
		list->head->next = NULL;
		list->tail = NULL;
	}
	else
	{
		Node* prev = list->head->next;
		while(prev->next != list->tail) prev=prev->next;
		prev->next = NULL;
		list->tail = prev;
	}
	list->size--;
}

//插入
bool insert_list(List* list,size_t index,TYPE val)
{
	if(0 >= index || index >= list->size) return false;
	Node* node = create_node(val);
	Node* prev = list->head->next;
	for(int i=1;inext;
	node->next = prev->next;
	prev->next = node;
	list->size++;
	return true;
}

//按值删除
bool del_val_list(List* list,TYPE val)
{
	if(val == list->head->next->date) return del_head_list(list);
	if(val == list->tail->date) return del_tail_list(list);
	for(Node* n=list->head->next;n->next;n=n->next)
	{
		if(val == n->next->date)
		{
			Node* temp = n->next;
			n->next = temp->next;
			free(temp);
			list->size--;
			return true;
		}
	}
	return false;
}

//按位置删除
bool del_index_list(List* list,size_t index)
{
	if(index >= list->size) return false;
	if(0 == index) return del_head_list(list);
	if(list->size-1 == index) return del_tail_list(list);
	Node* prev = list->head->next;
	for(int i=1;inext;	
	}
	Node* temp = prev->next;
	prev->next = temp->next;
	free(temp);
	list->size--;
	return true;
}

//按位置修改
bool modify_index_list(List* list,size_t index,TYPE val)
{
	 if(index >= list->size) return false;
	 Node* prev = list->head->next;
	 for(int i=0;inext;
	 prev->date = val;
	 return true;
		 
}

//按值修改
size_t modify_val_list(List* list,TYPE old,TYPE val)
{
	size_t cnt=0;
	for(Node* n=list->head->next;n;n=n->next)
	{
		if(n->date == old) 
		{
			n->date = val;
			cnt++;
		}
	}
	return cnt;
}

//查询
int query_list(List* list,TYPE val)
{
	int i = 0;
	for(Node* n=list->head;n->next;n=n->next)
	{
		if(val == n->next->date) return i;
		i++;
	}
	return -1;
}

//访问
bool access_list(List*list,size_t index,TYPE* val)
{
	if(index >= list->size) return false;
	Node* n = list->head->next;
	for(int i=0;inext;	
	}
	*val = n->date;
	return true;
}

//排序
void sort_list(List* list)
{
	for(Node* i=list->head->next;i->next;i=i->next)
	{
		for(Node* j=i->next;j;j=j->next)
		{
			if(i->next > j->next)
			{
				TYPE temp = i->date;
				i->date = j->date;
				j->date = temp;
			}
		}
	}
}

//清空
void clear_list(List* list)
{
	//while(list->size) del_tail_list(list);耦合依赖高
	while(list->head->next)
	{
		Node* temp = list->head->next;
		list->head->next = temp->next;
		free(temp);
	}
	list->tail = NULL;
	list->size = 0;
}

//销毁
void destory_list(List* list)
{
	clear_list(list);
	free(list->head);
	free(list);
}
//遍历
void show_list(List* list)
{
	for(Node* n=list->head->next;n;n=n->next)
	{
		printf("%d ",n->date);	
	}
	printf("n");
}
int main(int argc,const char* argv[])
{
	List* list = create_list();
	for(int i=0;i<10;i++)
	{
		add_head_list(list,i);	
	}
	show_list(list);
	del_head_list(list);
	show_list(list);
	del_tail_list(list);
	show_list(list);
	insert_list(list,1,99);
	show_list(list);
	del_val_list(list,99);
	show_list(list);
	del_index_list(list,1);
	show_list(list);
	modify_index_list(list,2,99);
	modify_index_list(list,3,99);
	show_list(list);
	modify_val_list(list,99,88);
	show_list(list);
	printf("%d",query_list(list,88));
}

静态链表：
    节点：
        数据域
        游标
    静态链表的节点存储在连续的内存中，通过游标来访问下一个节点
    这种链表在插入删除时只需要修改游标的的值，而不用申请、释放节点内存就可以达到类似链式结构的效果
    牺牲了随机访问的功能，也没法达到链表动态申请内存的效果，只是给没有指针的编程语言实现链表的一种方式，实用性不大

循环链表
    链表的最后一个节点的next不在指向NULL，而是指向头结点，这种链表称为单向循环链表，简称循环链表
    它的好处是可以通过任意一个节点遍历整个链表

双向循环链表
    节点
        前驱指针    prev
        数据域
        后继指针    next

#include 
#include 
#include 

#define TYPE int
//演示双向循环列表
typedef struct Node
{
	struct Node* prev;//前驱
	TYPE date;
	struct Node* next;//后继
}Node;

//创建
Node* create_node(TYPE date)
{
	Node* node=malloc(sizeof(Node));
	node->date = date;
	node->prev = node;
	node->next = node;
}
//带头结点
//依赖函数
void _add_list(Node* p,Node* n,TYPE date)
{
	Node* node = create_node(date);
	node->prev = p;
	node->next = n;
	p->next = node;
	n->prev = node;
}
//头添加
void add_head_list(Node* head,TYPE date)
{
	_add_list(head,head->next,date);
}

//尾添加
void add_tail_list(Node* head,TYPE date)
{
	_add_list(head->prev,head,date);	
}

//插入
bool insert_list(Node* head,size_t index,TYPE date)
{
	Node* n = head->next;
	for(int i=0;inext;
		if(head == n) return false;
	}
	_add_list(n->prev,n,date);
	return true;
}

//删除依赖函数
void _del_list(Node* node)
{
	Node* p = node->prev;
	Node* n = node->next;
	p->next = n;
	n->prev = p;
	free(node);
}
//值删除
bool del_val_list(Node* head,TYPE date)
{
	for(Node* n = head->next;head != n;n=n->next)
	{
		if(date == n->date)
		{
			_del_list(n);
			return true;
		}
	}
	return false;
}

//址删除
bool del_index_list(Node* head,size_t index)
{
	Node* n = head->next;
	for(int i=0;inext;
		if(head == n) return false;
	}
	_del_list(n);
	return true;
}
//遍历
void show_list(Node* head)
{
	for(Node* n=head->next;head != n;n=n->next)
	{
		printf("%d ",n->date);	
	}
	printf("n");
}

int main(int argc,const char* argv[])
{
	Node* head = create_node(0);
	for(int i=0;i<10;i++)
	{
		add_head_list(head,i);	
	}
	show_list(head);
	add_tail_list(head,99);
	show_list(head);
	insert_list(head,10,66);
	show_list(head);
	del_index_list(head,88);
	show_list(head);
	del_val_list(head,66);
	show_list(head);
}