链表2

#ifndef _LIST_H
#define _LIST_H

template<class Type> class List;

template<class Type>
class ListNode
{
	friend class List<Type>;
private:
	Type data;  // 节点里的数据，
	ListNode *link; // 指向下一个节点的数据，
	ListNode(Type);
};

template<class Type>
class List
{
public:
	List() { first = 0; }
	void Delete(Type);
	void Insert(Type);
	void Invert();  // 翻转，
	void Concatenate(List<Type>); // 链接，
	void Show();  // 测试用的，
private:
	ListNode<Type> *first;
};

template<class Type>
ListNode<Type>::ListNode(Type element)
{
	data = element; // 参数就是节点里的数据放到data里边，
	link = 0;
}


template<class Type>
void List<Type>::Insert(Type k)
{
	ListNode<Type> *newnode = new ListNode<Type>(k);
	newnode->link = first;  // 新的节点作为第一个节点，
	first = newnode;
}

template<class Type>
void List<Type>::Delete(Type k)
{
	ListNode<Type> *previous = 0; // 前一个，
	ListNode<Type> *current;
	for(current = first;
		current && current->data  != k;
		previous = current, current = current->link)
	{
		;// 什么都不做，空循环，找到要被删除的节点，
	}
		if(current)
		{
			if(previous) previous->link = current->link;
			else first = first->link;
			delete current;
		}
}

template<class Type>
void List<Type>::Concatenate(List<Type> b)
{
	if(!first) { first = b.first; return; }
	if(b.first)
	{
		ListNode<Type> *p;
		for(p = first; p->link; p = p->link);  // 空循环，
		p->link = b.first;
	}
}


template<class Type>
void List<Type>::Invert()
{
	ListNode<Type> *p = first, *q = 0;
	while(p)
	{
		ListNode<Type> *r = q; 
		q = p;
		p = p->link;
		q->link = r;
	}
	first = q;
}

template<class Type>
void List<Type>::Show()
{
	for(ListNode<Type> *current = first; current;current = current->link)
	{
		std::cout << current->data;
		if(current->link) std::cout << " -> ";
	}
	std::cout << std::endl;
}

#endif _LIST_H

#include <iostream>
#include "List.h"

using namespace std;

int main()
{
	List<int> intList;
	intList.Insert(31);
	intList.Insert(12);
	intList.Insert(3);
	intList.Insert(6);

	intList.Show();
	intList.Invert();
	intList.Show();

	intList.Delete(6);
	intList.Show();

	intList.Delete(60);
	intList.Show();


	List<char> charList;
	charList.Insert('x');
	charList.Insert('i');
	charList.Insert('a');
	charList.Insert('o');
	charList.Invert();
	charList.Show();


	List<char> charList2;
	charList2.Insert('c');
	charList2.Insert('u');
	charList2.Insert('i');
	charList2.Invert();
	charList2.Show();

	charList.Concatenate(charList2);
	charList.Show();

	return 0;
}