#ifndef _H_LIST
#define _H_LIST

#include <cstdlib>
using namespace std;

template<class T>
class CELEM {
protected:
    CELEM<T> *pNext;
    CELEM<T> *pPrev;
    T *pItem;
public:
    CELEM() {
        pNext = pPrev = NULL;
        pItem = NULL;
    }
    CELEM(CELEM<T>* pBefore, T*pI) {
        pItem = pI;
        pNext = pBefore->pNext;
        pPrev = pBefore;
        pBefore->pNext->pPrev = this;
        pBefore->pNext = this;
    }
    ~CELEM() {
        pNext->pPrev = pPrev;
        pPrev->pNext = pNext;/* delete pItem; */
    }
    CELEM<T>* getNext() {
        return pNext;
    }
    CELEM<T>* getPrev() {
        return pPrev;
    }
    T* getItem() {
        return pItem;
    }
};

template<class T>
class CLIST: public CELEM<T> {
public:
    CLIST() :
        CELEM<T> () {
        this->pNext = this->pPrev = this;
        this->pCurr = NULL;
    }
    int insHead(T*pI) {
        return (this->pCurr = new CELEM<T> (this, pI)) ? 1 : 0;
    }
    int insTail(T*pI) {
        return (this->pCurr = new CELEM<T> (this->pPrev, pI)) ? 1 : 0;
    }
    int insBef(T*pI) {
        return this->pCurr ? ((this->pCurr = new CELEM<T> (this->pCurr->getPrev(), pI)) ? 1
                : 0) : 0;
    }
    int insBeh(T*pI) {
        return this->pCurr ? ((this->pCurr = new CELEM<T> (this->pCurr, pI)) ? 1 : 0) : 0;
    }
    T* getFirst() {
        return (this->pCurr = this->pNext)->getItem();
    }
    T* getLast() {
        return (this->pCurr = this->pPrev)->getItem();
    }
    T* getNext() {
        return (this->pCurr ? ((this->pCurr = this->pCurr->getNext())->getItem()) : NULL);
    }
    T* getPrev() {
        return (this->pCurr ? ((this->pCurr = this->pCurr->getPrev())->getItem()) : NULL);
    }
    void remCurr() {
        delete this->pCurr;
        this->pCurr = NULL;
    }
    int insert(T* pI) {
        for (T* p0 = getFirst(); p0 && (*p0 < *pI); p0 = getNext())
            ;
        return (this->pCurr = new CELEM<T> (this->pCurr->getPrev(), pI)) ? 1 : 0;
    }
    ~CLIST() {
        T* p0;
        while (p0 = getFirst())
            remCurr();
    }
};

#endif