缘由

本人C++菜鸟一枚，打算一边复习数据结构、算法，一边学习C++。That’s All!

下面是C++链表的一个简单实现。

/*链表的增删改查*/
#include <iostream>
#include <string.h>
using namespace std;
#define LEN (16)
#define BUF (1024)

class node
{
public:
    char value[BUF];
    node *next;
};

class node_op
{
public:
    node *node_init( const char *value )
    {
        node *q = new node;
        strncpy( q->value, value, strlen( value ) );
        q->next = NULL;
        return q;
    }

    void node_free( node *q )
    {
        delete q;
    }

};

class list_op:public node_op
{
public:
    void list_init( node *list )
    {
        memset( list->value, 0, BUF );
        list->next = NULL;
    }

    void list_add( node *list, node *q, int p )
    {
        if ( !p )
        {
            p = 1;    //默认首部增加
        }

        if ( list->value[0] + 1 < p )
        {
            cout << "error: illegal position,current len is " << ( int )list->value[0] << endl; return; } list->value[0] ++;

        while ( --p )
        {
            list = list->next;
        }

        q->next = list->next;
        list->next = q;
    }

    void list_del( node *list, int p )
    {
        if ( !p )
        {
            p = 1;
        }

        if ( list->value[0]  < p )
        {
            cout << "error: illegal position,current len is " << ( int )list->value[0] << endl; return; } list->value[0] --;

        while ( --p )
        {
            list = list->next;
        }

        node *q = list->next;
        list->next = q->next;
        node_op op;
        op.node_free( q );
    }

    void list_modify( node *list, const char *value, int p )
    {
        if ( !p )
        {
            p = 1;
        }

        if ( list->value[0]  < p )
        {
            cout << "error: illegal position,current len is " << ( int )list->value[0] << endl; return; } while ( p-- ) { list = list->next;
        }

        memset( list->value, 0, strlen( list->value ) );
        strncpy( list->value, value, strlen( value ) );
    }

    void list_show( node *list, int p )
    {
        if ( !p )
        {
            p = 1;
        }

        if ( list->value[0]  < p )
        {
            cout << "error: illegal position,current len is " << ( int )list->value[0] << endl; return; } while ( p-- ) { list = list->next ;
        }

        cout << "value is " << list->value << endl;
    }

};

int main()
{
    node *list;
    list = new node;
    list_op op;
    op.list_init( list );
    //node *head = list;

    node *q = op.node_init( "test" );
    op.list_add( list, q, 1 );
    cout << "node:" << list->next->value << endl;

    node *p = op.node_init( "test2" );
    op.list_add( list, p, 2 );
    cout << "node:" << list->next->next->value << endl;

    node *r = op.node_init( "test4" );
    op.list_add( list, r, 2 );
    cout << "node:" << list->next->next->value << endl;

    op.list_del( list, 1 );
    cout << "node:" << list->next->value << endl;

    op.list_modify( list, "test1", 1 );
    cout << "node:" << list->next->value << endl; int i = ( int )list->value[0];

    while ( i )
    {
        op.list_show( list, i );
        i--;
    }

    delete list;
    return 0;
}