带头节点的单链表基本操作C++实现

//linked_list.cpp
#include <iostream>
using namespace std;
#define END -1	//插入法创建链表时的结束标志 

typedef int ElemType;	//取元素类型为int
//定义状态信息 
enum Status {
	ERROR = -1,
	SUCCESS = 0
};
//节点定义 
struct Node {
	ElemType data;
	Node *next;
};

class LinkedList {
	public :
		LinkedList();
		~LinkedList();
		Status CreateList_R();	//表尾插入法建立链表 
		Status CreateList_H();	//表头插入法建立链表 
		Status InsertElem(int loc, const ElemType e);	//在链表的指定位置插入元素 
		Status DeleteElem(int loc);						//删除链表指定位置的元素 
		Status GetElem(int loc, ElemType &e);			//获取链表指定位置的元素，通过引用方式传出 
		Node *Locate(const ElemType e);					//获取给定元素在链表中的位置，以指针形式给出 
		Node *GetHead();								//获取链表表头指针 
		int GetLength();								//获取链表长度 
		void printList();								//打印链表内元素数据值 
	private :
		Node *head;
};
//带头节点的链表初始化 
LinkedList::LinkedList() {
	head = new Node;
	head->next = NULL;
}
LinkedList::~LinkedList() {
	delete head;
}
//表尾插入法建立链表
Status LinkedList::CreateList_R() {
	ElemType x;
	cin >> x;
	Node *rear = head;
	while (x != END) {
		Node *s = new Node;
		s->data = x;
		rear->next = s;
		rear = s;
		rear->next = NULL;
		cin >> x;
	}
	return SUCCESS;
}
//表头插入法建立链表
Status LinkedList::CreateList_H() {
	ElemType x;
	cin >> x;
	while (x != END) {
		Node *s = new Node;
		s->data = x;
		s->next = head->next;
		head->next = s;
		cin >> x;
	}
	return SUCCESS;
}
//在链表的指定位置插入元素 
Status LinkedList::InsertElem(int loc, const ElemType e) {
	Node *p = head;
	int i = 0;
	while (i != loc - 1 && p != NULL) {
		p = p->next;
		i++;
	}
	if (p == NULL)
		return ERROR;
	Node *s = new Node;
	s->data = e;
	s->next = p->next;
	p->next = s;
	return SUCCESS;
}
//删除链表指定位置的元素
Status LinkedList::DeleteElem(int loc) {
	Node *p = head;
	int i = 0;
	while (i != loc - 1 && p != NULL) {
		p = p->next;
		i++;
	}
	if (p == NULL) {
		return ERROR;
	}
	Node *u = p->next;
	p->next = u->next;
	delete u;
	return SUCCESS;
}
//获取链表指定位置的元素，通过引用方式传出 
Status LinkedList::GetElem(int loc, ElemType &e) {
	Node *p = head;
	int i = 0;
	while (i != loc && p != NULL) {
		p = p->next;
		i++;
	}
	if (p == NULL) {
		return ERROR;
	}
	e = p->data;
	return SUCCESS;
}
//获取给定元素在链表中的位置，以指针形式给出 
Node *LinkedList::Locate(const ElemType e) {
	Node *p = head->next;
	while (p != NULL) {
		if (p->data = e) {
			return p;
		}
		p = p->next;
	}
	return NULL;
}
//获取链表表头指针 
Node *LinkedList::GetHead() {
	return head;
}
//获取链表长度 
int LinkedList::GetLength() {
	Node *p = head->next;
	int cnt = 0;
	while (p != NULL) {
		cnt++;
		p = p->next;
	}
	return cnt;
}
//打印链表内元素数据值 
void LinkedList::printList() {
	Node *p = head->next;
	while (p != NULL) {
		cout << p->data << " ";
		p = p->next;
	}
	cout << endl;
}

int main() {
	LinkedList L;
	int a, b, c, d;
	int x;
	cout << "请依次输入链表的元素值，以空格间隔， 输入-1以结束输入" << endl;
	L.CreateList_R();
//	L.CreateList_H();
	cout << "链表内的元素值依次为:" << endl;
	L.printList();
	cout << "链表的长度为:" << L.GetLength() << endl;
	/*
	cout << "请输入需要查找的元素:";
	cin >> x;
	cout << "元素的地址为:" << L.Locate(x) << ", 值为:" << L.Locate(x)->data << endl;
	*/
	cout << "请输入需要删除的元素的位置:";
	cin >> a;
	L.DeleteElem(a);
	cout << "修改后的链表内的元素值依次为:" << endl;
	L.printList();
	cout << "请输入需要删除的元素的位置:";
	cin >> b;
	L.DeleteElem(b);
	cout << "修改后的链表内的元素值依次为:" << endl;
	L.printList(); 
	cout << "请输入需要插入的元素及其位置(位置在前，元素在后，用空格隔开):";
	cin >> c >> d; 
	L.InsertElem(c, d);
	cout << "修改后的链表内的元素值依次为:" << endl;
	L.printList(); 
	return 0; 
}