单链表的c++实现

#include<iostream>
using namespace std;
template <class T>
struct Node //结点定义
{
 T data;
 Node<T> *next;
};
template<class T>
class Linklist
{
 Node<T> *head;
public:
 Linklist();     //不含参数构造
 Linklist(T a[], int i);//含参
 ~Linklist();  // 析构函数
 int listlength();//求长度
 T get(int i);//按位查找
 int locate(T x);//按值查找
 void Insert(int i, T item);//插入数据
 T Delete(int i); //删除数据
 void output();//输出
 void clear();//清空
};
template<class T>
Linklist<T>::Linklist()
{
 head = new Node<T>;
 head->next = NULL;
}
template<class T>
Linklist<T>::Linklist(T a[], int i)
{
 head = new Node<T>;
 Node<T> *p = head;
 for (int j = 0; j < i; j++)
 {
  Node<T> *s = new Node<T>;
  s->data = a[j];
  p->next = s;
  p = s;
 }
 p->next = NULL;
}
template<class T>
Linklist<T>::~Linklist()
{
 Node<T> *p = head;
 while (p)
 {
  Node<T> *q = p;
  p = p->next;
  delete q;
 }
 head = NULL;
}
template<class T>
int Linklist<T>::listlength()
{
 int sum = 0;
 Node<T> *p = head->next;
 while (p)
 {
  p = p->next;
  sum++;
 }
 return sum;
}
template<class T>
T Linklist<T>::get(int i)
{
 Node<T> *p = head->next;
 while (--i && p)
 {
  p = p->next;
 }
 if (!p || i < 0)
 {
  cout << "位置非法" << endl;
  exit(1);
 }
 else
  return p->data;
}
template<class T>
int Linklist<T>::locate(T x)
{
 Node<T> *p = head->next;
 int i = 1;
 while (p)
 {
  if (p->data == x)
   return i;
  p = p->next;
  i++;
 }
 exit(1);
}
template<class T>
void Linklist<T>::output()
{
 Node<T> *p = head->next;
 while (p)
 {
  cout << p->data << " ";
  p = p->next;
 }
}
template<class T>
T Linklist<T>::Delete(int n)//删除数据
{
 Node<T> *p = head;
 int j = 0;
 while (p&&j < n - 1)//找到第i-1个结点的位置
 {
  p = p->next;
  j++;
 }
 if (!p || !p->next)//位置合法性
 {
  cout << "错误位置" << endl;
  exit(1);
 }
 else
 {
  Node<T> *q = p->next;
  int x = q->data;
  p->next = q->next;
  delete q;
  return x;
 }
}
template<class T>
void Linklist<T>::Insert(int i, T item)
{
 Node<T> *p = head;
 int j = 0;
 while (p&&j < i - 1)
 {
  p = p->next;
  j++;
 }
 if (!p)
 {
  cout << "插入位置非法";
  exit(1);
 }
 else
 {
  Node<T> *s = new Node<T>;//生成元素值为item的新结点
  s->data = item;
  s->next = p->next;//用后插法将s插入到结点p的后面
  p->next = s;
 }
}
template<class T>
void Linklist<T>::clear()
{
 Node<T> *p = head;
 while (p)
 {
  Node<T> *q = p;
  p = p->next;
  delete q;
 }
 head = NULL;
}
int main()
{
 int a[5] = { 1,2,3,4,5 };
	cout << "初始化一个链表" << endl;
	Linklist<int> x(a, 5);
	x.output();
	cout << endl;
	cout << "在第一个位置插入元素 0" << endl;
	x.Insert(1, 0);
	x.output();
	cout << endl;
	cout << "删除第二个位置的元素" << endl;
	x.Delete(2);
	x.output();
	cout << endl;
	cout << "查找元素 3" << endl;
	cout<<"元素3的位置为："<<x.get(3)<<endl;
	x.clear();//清空
	system("pause");
	return 0;
}

测试结果：