链表

在下例中，演示了链表的各种操作

#include <iostream>
using namespace std;

typedef struct Node
{
    int data; //数据域
    struct Node * next; //指针域
}NODE, *PNODE;  //NODE相当于struct Node, PNODE相当于struct Node *

PNODE CreateList();
void TraverseList(PNODE pHead);
bool IsEmpty(PNODE pHead);
int NodeNumber(PNODE pHead);
void SortList(PNODE pHead);
bool InsertNode(PNODE pHead, int position, int value);
bool DeleteNode(PNODE pHead, int position);

int main()
{
    PNODE pHead = NULL;
    pHead = CreateList();
    TraverseList(pHead);
    if(IsEmpty(pHead))
        cout << "链表为空" << endl;
    else
        cout << "链表不为空" << endl;
    cout << endl;
    int nodeSum = NodeNumber(pHead);
    cout << "链表有" << nodeSum << "个节点" << endl;
    cout << "排序后数据分别为：";
    SortList(pHead);
    TraverseList(pHead);
    cout << "插入数据后，数据分别为：";
    InsertNode(pHead, 3, 22);
    TraverseList(pHead);
    cout << "删除数据后，数据分别为：";
    DeleteNode(pHead, 2);
    TraverseList(pHead);
    return 0;
}

PNODE CreateList()           //创建一个单链表
{
    int nodeNumber;
    int val;  //存放输入的每个节点的值

    PNODE pHead = new NODE;
    PNODE pTail = pHead;
    pTail->next = NULL;

    cout << "Enter the number of nodes you want to create: ";
    cin >> nodeNumber;

    if(pHead == NULL)
    {
        cout << "分配失败，程序终止." << endl;
    }

    for(int i=0; i<nodeNumber; i++)
    {
        cout << "The " << i+1 << "th node is ";
        cin >> val;

        PNODE pNew = new NODE;
        if(pNew == NULL)
        {
            cout << "分配失败，程序终止." << endl;
        }
        pNew->data = val;
        pTail->next = pNew;
        pNew->next = NULL;
        pTail = pNew;
    }
    return pHead;
}

void TraverseList(PNODE pHead)       //遍历链表
{
    PNODE p = pHead->next;
    cout << "数据分别为：";
    while(p != NULL)
    {
        cout << p->data << " ";
        p = p->next;
    }
    cout << endl;
}

bool IsEmpty(PNODE pHead)   //判断链表是否为空
{
    if(pHead->next == NULL)
        return true;
    else
        return false;
}

int NodeNumber(PNODE pHead)     //获取节点个数
{
    PNODE p = pHead->next;
    int nodeSum = 0;
    while(p != NULL)
    {
        nodeSum++;
        p = p->next;
    }
    return nodeSum;
}

void SortList(PNODE pHead)   //排序
{
    int i, j, t;
    PNODE p, q;
    int length = NodeNumber(pHead);
    for (i=0, p=pHead->next; i<length - 1; i++, p=p->next)
    {
        for(j=i+1, q=p->next; j<length; j++, q=q->next)
        {
            if(p->data > q->data)
            {
                t = p->data;
                p->data = q->data;
                q->data = t;
            }
        }
    }
}

bool InsertNode(PNODE pHead, int position, int value) //插入节点
{
    int i = 0;
    PNODE p = pHead;
    PNODE pNew = new NODE;
    int length = NodeNumber(pHead); //获取链表的节点个数
    if(position>0 && position<=length)
    {
        while(i<position)
        {
            p = p->next;
            i++;
        }
        pNew->data = value;
        PNODE q = p->next;
        p->next = pNew;
        pNew->next = q;
        return true;
    }
    else
        return false;
}

bool DeleteNode(PNODE pHead, int position)   //删除节点
{
    int i = 0;
    PNODE p = pHead;
    int length = NodeNumber(pHead);
    if(position>0 && position<=length)
    {
        while(i < position-1)
        {
            p = p->next;
            i++;
        }

    PNODE q = p->next->next;
    delete p->next;
    p->next = q;
    p->next = q;
    return true;
    }
    else
        return false;
}

运行结果为：

链表