c++实现算法链表

using namespace std;
struct Node 
{
    int data;
    Node *next;
};
Node* ( void )
{
    Node *head, *pre, *step;
    head = new Node;
    pre = head;
    int number;
    cin>>number;
    while ( number != -1 )
    {
        step = new Node;
        step->data = number;
        cout<<"get current number"<<step->data<<endl;
        pre->next = step;
        pre = step;
        cin>>number;
    } 
    head = head->next;
    pre->next = NULL;
    return head;
}
//获取单链表的长度
int getNodeLength( Node *head)
{
    int length = 0;
    if ( head == NULL )
    {
        cout<<"Error:head is null"<<endl;
        return 0;
    }
    Node *p;
    p = head;
    while ( p != NULL)
    {
        length++;
        p = p->next;
    }
    return length;
}
//显示单链表的结点
void listNodeValues( Node *head, int length)
{
    if ( head == NULL )
    {
        cout<<"Error: head is null"<<endl;
        return;
    }
    Node *current;
    current = head;
    while ( current != NULL )
    {
        cout<<"the "<<length<<"'s number is "<<current->data<<endl;
        length--;
        current = current->next;
    }
}
//删除指定值的结点
Node* deleteNodeChild( Node *head, int deleteNumber)
{
    if ( head == NULL )
    {
        cout<<"Error: head is null"<<endl;
        return head;
    }
    Node *current;
    current = head;
    if ( head->data == deleteNumber )
    {
        head = current->next;
        delete(current);
    } else 
    {
        while ( current->next != NULL &&  current->next->data != deleteNumber )
        {
            current = current->next;
        }
        Node *deleteNode = current->next;
        current->next = deleteNode->next;
        delete(deleteNode);
    }
    return head;
}
//在指定的值之前插入指定值的结点
Node* insertNodeChild( Node *head, int insertNodeBefore, int newNumber)
{
    if ( head == NULL ){
        head->data = newNumber;
        return head;
    }
    Node *current;
    current = new Node;
    current->data = newNumber;
    if ( head->data == insertNodeBefore )
    {
        current->next = head;
        return current;
    } else
    {
        Node *child = head;
        while ( child->next != NULL && child->next->data != insertNodeBefore )
        {gmia
            child = child->next;
        }
        if ( child->next == NULL )
        {
            child->next = current;
            current->next = NULL;
        } else 
        {
            current->next = child->next;
            child->next = current;
        }
    }
    return head;
}
//删除头结点
Node* removeNodeHead(Node *head)
{
    Node *p;
    p = head->next;
    delete(head);
    head = p;
    return head;
}
//获取单链表的中间结点
int getMiddleNumber(Node *head)
{
    Node *moveFast, *moveSlow;
    moveFast = head;
    moveSlow = head;
    while ( moveFast != NULL )
    {
        if ( moveFast->next == NULL || moveFast->next->next == NULL )
        {
            moveFast = NULL;
            moveSlow = moveSlow->next;
        } else 
        {
            moveFast = moveFast->next->next;
            moveSlow = moveSlow->next;
        }
    }
    return moveSlow->data;
}
//逆置单链表
Node* reverseNode(Node *head)
{
    Node *markNode, *tmpNode, *beforeNode;
    markNode = head;
    beforeNode = head;
    while ( markNode->next != NULL )
    {
        tmpNode = markNode->next;
        markNode->next = markNode->next->next;
        tmpNode->next = beforeNode;
        beforeNode = tmpNode;
    }
    head = beforeNode;
    return head;
}
//单链表结点排序
Node* sortNode(Node *head)
{
    Node *p1,*p2;
    int i, j, length,temp;
    length = getNodeLength(head);
    p1 = head->next;
    for ( i = 1;i < length;i++ )
    {
        p2 = head;
        for ( j = 0;j < i;j++ )
        {
            if ( p2->data > p1->data )
            {
                temp = p1->data;
                p1->data = p2->data;
                p2->data = temp;
            }
            p2 = p2->next;
        }
        p1 = p1->next;
    }
    return head;
}
int main ( int argc, char *argv[])
{
    Node *head;
    head = createNodeList();
    head = sortNode(head);
    int length = 0;
    length = getNodeLength(head);
    cout<<"get length "<<length<<endl;
    listNodeValues(head, length);
    return 0;
}