[게임알고리즘] 3-1강 링크 리스트

문자열을 추가, 삭제 가능한 링크리스트를 구현

 

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
 
struct Node
{
    const void* data;
    Node* prev;
};
 
Node* last = NULL;
 
int countNode();
 
void addNode(const void* data)
{
    Node* n = new Node;
    n->data = data;
    n->prev = last;
    
    last = n;
}
    
void addNode(int index, const void* data)
{
    int i = countNode() - 1;
    if( index==i )
    {
        addNode(data);
        return;
    }
    for(Node* p = last; p; p = p->prev, i--)
    {
        if(i==index)
        {
            Node* n = new Node;
            n->data = data;
            n->prev = p->prev;
            
            p->prev = n;
            return;
        }
    }
    printf("failed to insert node\n");
}
    
void delNode(int index)
{
    int i = countNode() - 1;
    for(Node* p = last,* back = NULL; p; 
        back = p, p = p->prev, i--)
    {
        if(i==index)
        {
            if( back )
                back->prev = p->prev;
            else// if( last==NULL )
                last = p->prev;
            delete p;
            return;
        }
    }
}
 
#if 0
 
bool delNode_(const void* data)
{
    for(Node* p = last, * back = NULL; p;
        back = p, p = p->prev)
    {
        if( p->data==data )
        {
            if( back )
                back->prev = p->prev;
            else
                last = p->prev;
            return true;
        }
    }
    return false;
}
void delNode(const void* data)
{
    while(delNode_(data));
}
 
#else
 
void delNode(const void* data)
{
    for(Node* p = last, * back = NULL; p;)
        //back = p, p = p->prev)
    {
        if( p->data==data )
        {
            if( back )
                back->prev = p->prev;
            else
                last = p->prev;
            //back = back;// 000
            Node* bk = p->prev;// 111
            delete p;
            p = bk;
        }
        else
        {
            back = p;// 000
            p = p->prev;// 111
        }
    }
}
#endif
    
void delAllNode()
{
    for(Node* p = last; p; )
    {
        Node* bk = p->prev;
        delete p;
        p = bk;
    }
    last = NULL;
}
 
const void* atNode(int index)
{
    int i = countNode() - 1;
    for(Node* p = last; p; p = p->prev, i--)
    {
        if( i==index )
            return p->data;
    }
    return NULL;
}
 
int countNode()
{
    int i=0;
    for(Node* p = last; p; p = p->prev, i++);
    return i;
}
 
int main() {
    
    const char* str[] = { "Hi", "world", "!!" };
    for(int i=0; i<3; i++)
        addNode(str[i]);
        
    addNode(0, str[0]);
 
    //delNode(2);
    delNode(str[0]);
    
    int count = countNode();
    for(int i=0; i<count; i++)
    {
        printf("nm[%d].data[%s]\n", i, (const char*)atNode(i));
    }
 
    return 0;
}

 

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