循環連結清單的實作 C++

自己寫的一個實作循環連結清單的小程式，功能不是特别多，實作了一些最基本的方法。

// circleList.cpp : 實作循環連結清單
//

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

using namespace std;

//定義節點
class Node
{
public:
	int data;
	Node *next;
};

//建立循環連結清單模闆
class circlelist
{
public:
	circlelist();
	~circlelist();
	void createList();
	void travelList();
	int deleteList(int index);
	int insertList(int index, int x);
	int 

private:
	Node *head;
};

//構造函數，初始化循環連結清單
circlelist::circlelist()
{
	//建立一個指向自己本身的結點
	head = new Node();
	head->data = 0;
	head->next = head;
	printf("這裡是構造函數，初始化連結清單\n");
}

//析構函數
circlelist::~circlelist()
{
	delete head;
	printf("這裡是析構函數\n");
}

//建立循環連結清單
void circlelist::createList()
{
	Node *p,*q;
	p = head;
	printf("請輸傳入連結表的長度:");
	int n;
	cin >> n;
	int data;
	if (n==0)
	{
		printf("結束建立\n");
		return;
	}
	else
	{
		for (size_t i = 1; i <= n; i++)
		{
			q = (Node*)malloc(sizeof(Node));
			printf("請輸入第%d個連結清單的資料:", i);
			cin >> data;
			q->data = data;
			p->next = q;
			q->next = head;
			p = q;
		}
		return;
	}
}

//周遊連結清單
void circlelist::travelList()
{
	Node *p;
	p = head;
	int n = 1;
	printf("頭結點的資料是：%d\n", p->data);
	while (p->next!=head)
	{
		p = p->next;
		printf("第%d個結點的資料是：%d\n", n,p->data);
		n++;
	}
}

//删除連結清單第index個元素，如果index不存在，則傳回-1
int circlelist::deleteList(int index)
{
	Node *p;
	p = head;
	int n = 0;
	while (p->next!=head)
	{
		n++;
		if (index==n)
		{
			p->next = p->next->next;
			printf("删除成功！\n");
			return 0;
		}
		p = p->next;
	}
	if (index>n)
	{
		printf("所删除元素超對外連結表長度！\n");
		return -1;
	}
}

//在第index個位置之前插入資料val，如果index超出長度，則不會插傳入連結表，index等于連結清單長度，則插在最末尾
int circlelist::insertList(int index, int x)
{
	Node *p,*q;
	p = head;
	int n = 0;
	while (p->next!=head)
	{
		p = p->next;
		n++;
	}
	int length = n;
	if (index<length)
	{
		p = head;
		int n = index;
		while (--n)//此處要用--n，先自減，再判斷值
		{
			p = p->next;
		}
		q = (Node*)malloc(sizeof(Node));
		q->data = x;
		q->next = p->next;
		p->next = q;
		return 1;
	}
	if (index==length)
	{
		p = head;
		int n = index;
		while (n)
		{
			p = p->next;
			n--;
		}
		q = (Node*)malloc(sizeof(Node));
		q->data = x;
		q->next = p->next;
		p->next = q;
		return 2;
	}
	if (index >length)
	{
		return 0;
	}
	return 0;
}


int main()
{
	circlelist List;
	List.createList();
	List.travelList();
	printf("輸入要删除連結清單的元素：");
	int x;
	cin >> x;
	List.deleteList(x);
	List.travelList();
	printf("選擇在第幾個結點前插傳入連結表：");
	int y;
	cin >> y;
	List.insertList(y, 99);
	List.travelList();
    return 0;
}