#include<iostream>
    using namespace std;
    typedef struct elem {
                        int info;
                        struct elem *pred,*urm;
                        } element;
    typedef struct {
                    element *st,*cr,*sf;
                    int lung;
                   } dubla;
    dubla L;
    int n;


    int printme(dubla lista,int direction)
    {
        cout<<endl;
        if (direction==1)
        {
            element *plimb;
            plimb=lista.st;
            while (plimb!=NULL) {
                    cout<<plimb->info<<" ";plimb=plimb->urm;
                                }
        return 1;
        }
        else
        if (direction==0)
        {
            element *plimb;
            plimb=lista.sf;
            while (plimb!=NULL) {
                    cout<<plimb->info<<" ";plimb=plimb->pred;
                                }
        return 1;
        }
        else return 0;
    }


    dubla initlist()
    {
        dubla somelist;
        somelist.lung=0;
        somelist.st=somelist.cr=somelist.sf=NULL;
        return somelist;

    }

    int isempty(dubla lista)
    {
        return (lista.lung==0);
    }

    int foundme(dubla *lista, int valoare)
    {
            element *plimb;
            if (!isempty(*lista))
            {
                plimb=lista->st;
                int gasit=0;
                while ((!gasit)&&(plimb!=NULL))
                {
                    if (plimb->info==valoare) { gasit=1;}
                    else plimb=plimb->urm;
                }
                if (gasit) { lista->cr=plimb; return 1;}
                else return 0;
            }
            else return 0;
    }


    dubla addme(dubla lista,int nou,int direction)
    {
        if (direction==1)
        {
        if (!isempty(lista))
              {
                    element *adaugat=new element;
                    adaugat->info=nou;
                    if (lista.cr!=lista.sf)
                                {
                                 element *stanga,*dreapta;
                                 stanga=lista.cr;
                                 dreapta=lista.cr->urm;
                                 stanga->urm=adaugat;
                                 adaugat->pred=stanga;
                                 adaugat->urm=dreapta;
                                 dreapta->pred=adaugat;
                                 lista.lung++;
                                 lista.cr=adaugat;
                                 return lista;
                                }
                     else
                     {//curent=sfarsit
                      element *stanga;
                      stanga=lista.cr;
                      stanga->urm=adaugat;
                      adaugat->pred=stanga;
                      adaugat->urm=NULL;
                      lista.cr=adaugat;
                      lista.sf=adaugat;
                      lista.lung++;
                      return lista;
                     }
             }
           else
           { // vida !
                      element *adaugat=new element;
                      adaugat->info=nou;
                      adaugat->pred=NULL;
                      adaugat->urm=NULL;
                      lista.st=lista.cr=lista.sf=adaugat;
                      lista.cr=adaugat;
                      lista.lung++;
                      return lista;

           }
        }
        else
        //!!!!!!!
        {// la stanga curentului  !
        if (!isempty(lista))
              {
                    element *adaugat=new element;
                    adaugat->info=nou;
                    if (lista.cr!=lista.sf)
                                {
                                 element *stanga,*dreapta;
                                 dreapta=lista.cr;
                                 stanga=lista.cr->urm;
                                 dreapta->urm=adaugat;
                                 adaugat->pred=dreapta;
                                 adaugat->urm=stanga;
                                 dreapta->pred=adaugat;
                                 lista.lung++;
                                 lista.cr=adaugat;
                                 return lista;
                                }
                     else
                     {//curent=sfarsit
                      element *stanga;
                      stanga=lista.cr;
                      stanga->urm=adaugat;
                      adaugat->pred=stanga;
                      adaugat->urm=NULL;
                      lista.cr=adaugat;
                      lista.sf=adaugat;
                      lista.lung++;
                      return lista;
                     }
             }
           else
           { //vida !
                      element *adaugat=new element;
                      adaugat->info=nou;
                      adaugat->pred=NULL;
                      adaugat->urm=NULL;
                      lista.st=lista.cr=lista.sf=adaugat;
                      lista.cr=adaugat;
                      lista.lung++;
                      return lista;

           }
        }
    }

    dubla delme(dubla lista,int direction)
    {
        if (direction==1)
        {
        element *stanga,*dreapta;
        stanga=lista.cr->pred;
        dreapta=lista.cr->urm;
        delete lista.cr;
        stanga->urm=dreapta;
        dreapta->pred=stanga;
        lista.cr->info=dreapta->info;
        lista.cr->urm=dreapta->urm;
        lista.cr->pred=dreapta->pred;
        lista.lung--;
        return lista;
        }
        else if(L.cr->urm==NULL)
        {
            element *stanga;
            stanga=lista.cr->pred;
            delete lista.cr;
            stanga->urm=NULL;
            lista.cr->urm=stanga->urm;
            lista.cr->info=stanga->info;
            lista.cr->pred=stanga->pred;
            lista.lung--;
            return lista;
        }
        else if(L.cr->pred==NULL)
        {
            element *dreapta;
            dreapta=lista.cr->urm;
            delete lista.cr;
            dreapta->pred=NULL;
            lista.cr->urm=dreapta->urm;
            lista.cr->info=dreapta->info;
            lista.cr->pred=dreapta->pred;
            lista.lung--;
            return lista;
        }
        else
        if (direction==0)
        {
       element *stanga,*dreapta;
        stanga=lista.cr->pred;
        dreapta=lista.cr->urm;
        delete lista.cr;
        stanga->urm=dreapta;
        dreapta->pred=stanga;
        lista.cr->info=stanga->info;
        lista.cr->urm=stanga->urm;
        lista.cr->pred=stanga->pred;
        lista.lung--;
        return lista;
        }
        else return lista;
    }


    int main()
    {
        int somevalue;
        int right=1;
        int left=0;
        L=initlist();
        cout<<"N=";cin>>n;
        for(int i=1;i<=n;i++) L=addme(L,i,right);
        printme(L,right);
        printme(L,left);
        cout<<" Value = ";cin>>somevalue;
        foundme(&L,somevalue);

        cout<<endl<<" Current "<<L.cr->info<<endl;
        printme(L,right);
        printme(L,left);

        delme(L,0);
        cout<<endl<<" Current "<<L.cr->info<<endl;
        printme(L,right);
        printme(L,left);

        delme(L,0);
        cout<<endl<<" Current "<<L.cr->info<<endl;
        printme(L,right);
        printme(L,left);


        return 0;
    }