抽象类输出问题

Question

这个主程序应该要求用户输入一些数字并将它们存储到一个动态数组中。然后应该以直线输出数组的内容，没有结束行命令，中间有逗号。我不知道如何启动程序。

如果你们能帮我找到方法，我将永远感激不尽！

这里是 ListType.h：

#ifndef LISTTYPE_H_INCLUDED
#define LISTTYPE_H_INCLUDED
#include <iostream>

class ListType {
public:
 ListType(size_t=10);
 virtual ~ListType();
 virtual bool insert(int)=0;
 virtual bool erase();
 virtual bool erase(int)=0;
 virtual bool find(int) const=0;
 size_t size() const;
 bool empty() const;
 bool full() const;
 void output(std::ostream& out) const;
 friend std::ostream& operator << (std::ostream&, const ListType&);
protected:
 int *items;
 size_t capacity;
 size_t count;
};

#endif // LISTTYPE_H_INCLUDED

这里是 UListType.h：

#ifndef ULISTTYPE_H_INCLUDED
#define ULISTTYPE_H_INCLUDED
#include <iostream>

class UListType: public ListType {
public:
 UListType(size_t=10);
 bool insert(int);
 bool erase(int);
 bool find(int) const;
};


#endif // ULISTTYPE_H_INCLUDED

这里是 OListType.h：

#ifndef OLISTTYPE_H_INCLUDED
#define OLISTTYPE_H_INCLUDED
#include <iostream>

class OListType: public ListType {
public:
 OListType(size_t=10);
 bool insert(int);
 bool erase(int);
 bool find(int) const;
};


#endif // OLISTTYPE_H_INCLUDED

这里是 ListType.cpp：

#include "ListType.h"

ListType::ListType (size_t a) {
 capacity = a;
 count = 0;
 items = new int [capacity];
}

ListType::~ListType() {
 delete [] items;
}

bool ListType::erase() {
 count = 0;
 return 0;
}

size_t ListType::size() const {
 return (count);
}

bool ListType::empty() const {
 return (count == 0);
}

bool ListType::full() const {
 return (count == capacity);
}

void ListType::output(std::ostream& out) const {
 for (int i = 0; i < count; i++) {
      if (i > 0) {
        out << ", ";
      }
      out << items[i];
 }
}

std::ostream& operator << (std::ostream& out, const ListType& my_list) {
 my_list.output(out);
   return out;
}

这里是 UListType.cpp

#include "ListType.h"
#include "UListType.h"

UListType::UListType (size_t c): ListType(c) {}

bool UListType::insert(int item) {
 if (full()) {
    int *newitems;
    capacity *=2;
    newitems = new int[capacity];
    for (size_t i =0; i < count; ++i){
        newitems[i] = items[i];
    }
    delete [] items;
    items = newitems;
 }
 items[count++] = item;
 return true;
}

bool UListType::erase(int item) {
 bool result = false;
 size_t i=0;
 while ( i < count && items [i] != item) {
     ++i;
}
 if (i < count) {
    items[i] = items[-- count];
    result = true;
 }
 return result;
}

bool UListType::find(int item) const {
 size_t i = 0;
 while (i < count && items [i] != item) {
     ++i;
 }
 return i;
}

这里是 OListType.cpp

#include "ListType.h"
#include "OListType.h"

OListType::OListType(size_t c): ListType(c) {}

bool OListType::insert(int item) {
 size_t i = count;
 if (full()) {
    int *newitems;
    capacity *=2;
    newitems = new int[capacity];
    while (i > 0 && items[i-1] > item){
        newitems[i] = items[i];
    }
    delete [] items;
    items = newitems;
 }
 items[count++] = item;
 return true;
}

bool OListType::erase(int item) {
 bool found=false;
 size_t i=0, j= count-1, mid;
 while (i <= j && !(found)){
    mid = (i + j)/2;
    if (item < items [mid])
        j = mid - 1;
    else if (item > items [mid])
        i = mid + 1;
    found = items [mid] == item;
}
if (found) {
    for (i = mid; i < count - 1; ++i) {
        items [i] = items [i +1];
    }
     --count;
 }
 return found;
}

bool OListType::find (int item) const {
bool found=false;
 size_t i=0, j= count-1, mid;
 while (i <= j && !(found)){
    mid = (i + j)/2;
    if (item < items [mid])
        j = mid - 1;
    else if (item > items [mid])
        i = mid + 1;
    found = items [mid] == item;
 }
 return found;
}

Answer 1

#include "ListType.h"
#include "UListType.h"

#include <iostream>
using std::cout;
using std::endl;
using std::cin;

int main()
{
  UListType UL;

  cout << "How many numbers do you want to put it?" << endl;
  int n;
  cin >> n;
  cout << "All right, enter " << n << " numbers:" << endl;
  int x;
  for(int k=0; k<n; ++k)
  {
    cin >> x;
    // do something with x
  }
  return(0);
}

Answer 2

您已经拥有所需的一切。试试下面的

#include <iostream>
#include "OListType.h"

using namespace std;
int main()
{
    OListType list;
    int n;
    do
    {
        cout << "Add a number [Y/n]?";
        char a;
        cin >> a;
        if (a != 'n')
        {
            cin >> n;
            list.insert(n);
        }
        else
        {
            list.output(cout);
            break;
        }
    }while (1);

    return 0;
}