带头节点的链表的各种代码

typedef int ElemType;
typedef struct LinkNode
{
	int data;
	struct LinkNode* next;
}ListNode, *Linklist;
ListNode* InitList() // 初始化链表，给链表设置表头
{
	ListNode* sp = (ListNode*)malloc(sizeof(ListNode));
	sp->next = NULL;
	sp->data = 0;
	return sp;
}
bool IsEmpty(Linklist head) //判断链表是否为空
{
	assert(head != NULL);
	return head->next == NULL;
}
int GetSize(Linklist head) //计算链表中元素个数
{
	assert(head != NULL);
	int i = 0;
	LinkNode* sp = head->next;
	while (sp != NULL)
	{
		sp = sp->next;
		i += 1;
	}
	return i;
}
void PrintList(Linklist head) //打印链表
{
	assert(head != NULL);
	ListNode* sp = head;
	while (sp->next != NULL)
	{
		sp = sp->next;
		printf("%3d", sp->data);
	}
	printf("\n");
}
ListNode* FindValue(Linklist head, ElemType val) //返回指定值的地址
{
	assert(head != NULL);
	ListNode* sp = head->next;
	while (sp != NULL && sp->data == val)
	{
		sp = sp->next;
	}
	return sp;
}
ListNode* FindValue_Prev(Linklist head, ElemType val) //返回指定值的前一个值地址
{
	assert(head != NULL);
	ListNode* sp = head->next;
	ListNode* s = head;
	while (sp != NULL && sp->data == val)
	{
		s = s->next;
		sp = sp->next;
	}
	if (NULL == sp) 
	{
		s = NULL;
	}
	return s;
}
ListNode* FindPos(Linklist head, int pos) //返回指定位置的地址
{
	assert(head != NULL);
	ListNode* sp = head->next;
	int i = 1;
	if (pos < 1) return NULL;
	while (sp != NULL && i < pos)
	{
		sp = sp->next;
		i++;
	}
	return sp;
}
ListNode* FindPos_Prev(Linklist head, int pos) //返回指定位置的前一个值地址
{
	assert(head != NULL);
	ListNode* sp = head->next;
	ListNode* s = head;
	int i = 1;
	if (pos < 1) return NULL;
	while (sp != NULL && i < pos)
	{
		s = s->next;
		sp = sp->next;
		i += 1;
	}
	if (pos > i)
	{
		s = NULL;
	}
	return s;
}
bool Insert_Next(Linklist head, ListNode* ptr, ElemType val) //在指定位置插入数值
{
	assert(head != NULL);
	if (ptr == NULL) return false;
	ListNode* sp = (ListNode*)malloc(sizeof(ListNode));
	if (sp == NULL) return false;
	sp->data = val;
	sp->next = ptr->next;
	ptr->next = sp;
	return true;
}
void Pust_Front(Linklist head, ElemType val) //从链表头插入
{
	assert(head != NULL);
	Insert_Next(head, head, val);
}
void Push_Back(Linklist head, ElemType val) //从链表后面插入
{
	assert(head != NULL);
	ListNode* sp = head;
	while (sp->next != NULL)
	{
		sp = sp->next;
	}
	Insert_Next(head, sp, val);
}
bool InsertPos(Linklist head, int pos, ElemType val) //在指定位置插入值
{
	assert(head != NULL);
	if (pos < 1) return false;
	int i = 1;
	ListNode* sp = head;
	while (sp != NULL && i < pos)
	{
		sp = sp->next;
		i += 1;
	}
	if (pos > i) return false;
	Insert_Next(head, sp, val);
	return true;
}
bool Erase_Next(Linklist head, ListNode* ptr) //删除指定位置后一个节点
{
	assert(head != NULL);
	ListNode* sp = NULL;
	if (ptr == NULL || ptr->next == NULL)
	{
		return false;
	}
	sp = ptr->next;
	ptr->next = ptr->next->next;
	free(sp);
	sp = NULL;
	return true;
}
void Pop_Back(Linklist head) //从后往前删
{
	assert(head != NULL);
	ListNode* sp = head->next;
	ListNode* s = head;
	if (sp == NULL) return;
	while(sp->next != NULL)
	{
		s = sp;
		sp = sp->next;
	}
	Erase_Next(head, s);
}
bool Remove(Linklist head, ElemType val) //移除链表中第一个指定值
{
	assert(head != NULL);
	return Erase_Next(head, FindValue_Prev(head,val));
}
void Remove_ALL(Linklist head, ElemType val) // 移除链表中所有指定值
{
	assert(head != NULL);
	LinkNode* sp = head->next;
	LinkNode* s = head;
	while (sp != NULL)
	{
		if (sp->data == val)
		{
			s->next = sp->next;
			free(sp);
			sp = s->next;
		}
		else
		{
			s = sp;
			sp = sp->next;
		}
	}
}
void ClearList(Linklist head) // 清除链表不连头节点
{
	assert(head != NULL);
	LinkNode* sp = head->next;
	LinkNode* s = head;
	while (sp != NULL)
	{
		s->next = sp->next;
		free(sp);
		sp = s->next;
	}
}
void ClearList_1(Linklist head) // 清除链表不连头节点
{
	assert(head != NULL);
	while (!IsEmpty(head))
	{
		Pop_Back(head);
	}
}
void DestoryList(Linklist head) // 摧毁链表连头节点
{
	assert(head != NULL);
	ClearList(head);
	free(head);
	head = NULL;
}
void ReverseList_1(Linklist head) // 三指针方法逆置链表
{
	assert(head != NULL);
	LinkNode* pre = NULL;
	LinkNode* s = NULL;
	LinkNode* p = head->next;
	while (p != NULL)
	{
		s = p;
		p = p->next;
		s->next = pre;
		pre = s;
	}
	head->next = pre;
}
void ReverseList_2(Linklist head) // 二指针方法逆置链表
{
	assert(head != NULL);
	LinkNode* sp = head->next;
	LinkNode* s = NULL;
	head->next = NULL;
	while (sp != NULL)
	{
		s = sp;
		sp = sp->next;
		s->next = head->next;
		head->next = s;
	}
}
void ReverseList_3(Linklist head) // 用栈的方法，逆置链表
{
	assert(head != NULL);
	if (head->next == NULL || head->next->next == NULL)
	{
		return;
	}
	int len = 0;
	ListNode* p = head->next;
	while (p != NULL)
	{
		len++;
		p = p->next;
	}
	int* stack = (int*)malloc(sizeof(int) * len);
	int top = -1;
	p = head->next;
	while (p != NULL)
	{
		top += 1;
		stack[top] = p->data;
		p = p->next;
	}
	p = head->next;
	while (p != NULL)
	{
		p->data = stack[top];
		top = top - 1;
		p = p->next;
	}
}
ListNode* Reverse(ListNode* p)
{
	if (p == NULL || p->next == NULL)
	{
		return p;
	}
	ListNode* fp = Reverse(p->next);
	p->next->next = p;
	p->next = NULL;
	return fp;
}
void ReverseList_4(Linklist head) //用递归方式逆置链表
{
	assert(head != NULL);
	ListNode* p = head->next;
	head->next = Reverse(p);
}

int main()
{
	int ar[] = { 12 ,23,34,45,56,12,23,12,12,12,78,12 };
	int n = sizeof(ar) / sizeof(ar[0]);
	Linklist head = InitList();
	for (int i = 0; i < n; i++)
	{
		Push_Back(head, ar[i]);
	}
	PrintList(head);
	ReverseList_2(head);
	PrintList(head);
	return 0;
}