Двусвязный список структур - C++ - Ответ 184766

#include <iostream>
#include <conio.h>
#include <stdio.h>
#include <malloc.h>
 
using namespace std;
 
struct Item
{
    char itsName[10];
    int itsPrice;
    int itsCount;
    Item* itsNext;
    Item* itsPrev;
};
 
struct List
{
    Item* itsFirst;
  Item* itsLast;
};
 
void menu();
void AddItem(List&);
void DeleteItem(List&);
void PrintList(List*);
void CreateList (List*&);
List* theList = 0;
 
int main()
 
{
List* itsFirst=0;
List* itsLast=0;
   menu();
   getche();
   return 0;
}
 
void menu()
{
    bool quit = false;
    while (true)
    {
    int choice;
    printf("\n ******* MENU *********** \n" );
    printf("(1) vvedite spisok \n" );
    printf("(2) prosmotr \n");
    printf("(3) dobavlenie \n");
    printf("(4) udalenie \n");
    printf("(5) vyhod \n" );
 
    scanf("%d",&choice);
 
    switch (choice)
    {
    case(1):
        if (!theList)
        {
            CreateList (theList);
            printf(" the List has been created succesfully... \n");
        }
        else
            printf(" the List is already created...\n" );
        break;
    case(2):
        if (theList)
            PrintList(theList);
        else
            printf(" the List is not created...\n");
        break;
    case(3):
        if (theList)
            AddItem(*theList);
        else
            printf(" the List is not created...\n");
        break;
    case 4:
        if (theList)
            DeleteItem(*theList);
        else
            printf(" the List is not created... \n");
        break;
    case(5):
        quit = true;
    }
    if (quit == true)
        break;
    }
}
 
 
void AddItem(List& theList)
{
    printf("\n *** dobavit' novuy tovar *** \n");
    printf(" vvedite nazvanie: ");
    Item* newItem = new Item;
    scanf("%s",&newItem->itsName);
    printf(" vvedite cenu: ");
    scanf("%d",&newItem->itsPrice);
    printf(" vvedite kolichestvo: ");
    scanf("%d",&newItem->itsCount);
    if (theList.itsLast)
    {
        theList.itsLast->itsNext = newItem;
        newItem->itsPrev = theList.itsLast;
    }
    else
    {
        theList.itsFirst = newItem;
        newItem->itsPrev = 0;
    }
    theList.itsLast = newItem;
    newItem->itsNext = 0;
    printf("*** item was added successfully *** \n");
}
 
 
void CreateList (List*& theList)
{
   theList = new List;
   theList->itsFirst = NULL;
   theList->itsLast = NULL;
   Item *p,*k=NULL;
 
   do
    {
    p = new Item;
  printf( "*** vvedite tovar *** \n");
  printf(" vvedite nazvanie: ");
  scanf("%s", &p->itsName);
  printf( " vvedite cenu: " );
  scanf("%d", &p->itsPrice);
  printf(" vvedite kolichestvo: ");
  scanf( "%d",&p->itsCount);
 
    if(theList->itsFirst==NULL) theList->itsFirst = p;
 
    p->itsNext = NULL;
    if(k)
     {
      p->itsPrev = k;
      k->itsNext = p;
     }
     else
      {
       p->itsPrev = NULL;
      }
 
    k = p;
 
    puts(" Zakonchit' - <esc>");
    }
 while (getch()!=27);
 
    theList->itsLast=p;
}
 
 
void PrintList(List* theList)
{
    printf("\n *** prosmotr spiska *** \n");
    Item* curItem = theList->itsFirst;
    while (curItem)
    {
       // printf("%s\n",curItem->itsName);
      //  printf("%f\n",&curItem->itsPrice);
       // printf("%d\n",&curItem->itsCount);
      //  curItem = curItem->itsNext;
     printf("\n   %s   %d   %d ",curItem->itsName,curItem->itsPrice,curItem->itsCount);
      curItem = curItem->itsNext;
    }
    printf("\n *** end *** \n" );
}
 
void DeleteItem(List& theList)
{
    Item* curItem = theList.itsFirst;
    int Pos;
    printf( " Enter the position of deleted item: \n");
    scanf("%d",&Pos);
    printf("%d",Pos);
    for (int i=0; i<Pos ; i++)
    {
        if (curItem)
            curItem = curItem->itsNext;
    }
    if (curItem && (Pos >= 0))
    {
        if (curItem->itsPrev)
        {
            curItem->itsPrev->itsNext = curItem->itsNext;
        }
        else
        {
            theList.itsFirst = curItem->itsNext;
        }
        if (curItem->itsNext)
        {
            curItem->itsNext->itsPrev = curItem->itsPrev;
        }
        else
        {
            theList.itsLast = curItem->itsPrev;
        }
        delete curItem;
        printf("Item ? ", Pos ," has been deleted successfully..." );
    }
    else
        printf("Item ? ", Pos , " not found..." );
 
}