新人友好型C++实现单链表；附链表翻转；

还记得刚接触算法的时候，觉得看视频太慢，在网上找了好几个单链表的C++实现，发现一千个人，一千个C++代码风格。所以自己也写了一个代码，为代码基数+1，相信新人总能在某一款中发现新思路，豁然开朗。

因为代码不多，结构比较简单，函数的声明和实现放一起了，感觉看起来更方便吧。希望能有用！如有纰漏，也欢迎各位大佬批评指正！

话不多说，直接上代码。

#include <string>
#include <iostream>
using namespace std;

class Node
{
public:
	int m_data;
	Node* m_next;

	Node(int data = 0,Node* next = nullptr) 
	{
		m_data = data;
		m_next = next;
	}
};

class LinkList 
{

	int size;		
	Node head;

public:

	LinkList() 
	{
		size = 0;
	}

	~LinkList() 
	{
		this->clear();
	}

	void append_element(int data) 
	{
		Node* newnode = new Node;		
		Node* temp = head.m_next;		//为遍历链表创建的一个临时变量
		if (head.m_next == nullptr)		
		{
			head.m_next = newnode;
			newnode->m_data = data;
			size++;
		}
		else
		{
			while (1)
			{
				if (temp->m_next == nullptr)
				{
					newnode->m_data = data;
					temp->m_next = newnode;
					size++;
					break;
				}
				temp = temp->m_next;
			}
		}
	}

	int traval() 
	{
		Node* temp = head.m_next;
		if (size == 0)
		{
			return 0;
		}
		while (1)
		{
			cout << temp->m_data << "->";
			if (temp->m_next == nullptr)	break;
			temp = temp->m_next;
		}
		cout << "nullptr" << endl;
	}

	void getsize() 
	{
		cout << "The LinkList's size = " << size << endl;
	}

	void insert(int data,int position) 
	{
		if (position < 0 || position >= size)	cout << "Index is out of range." << endl;

		else if (position == 0)  //头插 计数从0开始，这很程序员
		{
			Node* newnode = new Node;
			Node* temp;

			temp = head.m_next;
			head.m_next = newnode;
			newnode->m_next = temp;
			newnode->m_data = data;

			size++;
		}

		else if (position == size - 1)  //尾插  为什么不用append？
		{
			Node* newnode = new Node;
			Node* temp = head.m_next;

			while (1)
			{
				if (temp->m_next == nullptr)
				{
					temp->m_next = newnode;
					newnode->m_data = data;
					size++;
					break;
				}
				temp = temp->m_next;
			}
		}

		else
		{
			Node* newnode = new Node;
			Node* cur = head.m_next;
			Node* temp;

			for (size_t i = 0; i < position - 1; i++)		cur = cur->m_next;
			temp = cur->m_next;
			cur->m_next = newnode;
			newnode->m_next = temp;
			newnode->m_data = data;
			size++;
		}
	}
	
	void reverse()
	{
		Node* cur = head.m_next;
		Node* pre = nullptr, * next;
		
		while (true)
		{
			next = cur->m_next;
			cur->m_next = pre;
			pre = cur;
			cur = next;
			if (cur == nullptr)
				break;
		}
		head.m_next = pre;
		
	}

	void clear() 
	{
		Node* cur = head.m_next;
		Node* temp;
		while (true)
		{
			temp = cur->m_next;
			delete cur;
			cur = temp;
			if (cur == nullptr)
				break;
		}
		size = 0;
	}
};

int main() 
{
	LinkList test;
	test.append_element(5);
	test.append_element(10);
	test.append_element(15);
	test.traval();
	test.getsize();
	test.insert(20, 0);
	test.traval();
	test.getsize();
	test.insert(30, 3);
	test.traval();
	test.insert(1, 2);
	test.traval();
	test.reverse();
	test.traval();
	test.clear();
	test.traval();

}