new int []引发“访问冲突”异常

| 我一直在研究自定义Vector类。一切在Microsoft编译器上都可以正常运行,但是当我在Borland上尝试时,我遇到了一个非常奇怪的错误。 Borland在insert函数中引发异常; 正是在调用复制构造函数\“ Vector temp(* this); \”时 \“ array_ = new int [rhs.size _]; \”行
void Vector::insert(int value, unsigned position) throw(SubscriptError)
{
    check_bounds(position);
    Vector temp(*this);
    int tmpSize= size_;
    temp.size_++;
    size_++;
    for (unsigned int i=tmpSize; i > position; i--)
    {
        temp[i] = temp[i-1];
    }
    temp[position] = value;

   //array_= temp.array_;
    for(unsigned int i = 0; i < size_; i++)
    {
        array_[i]= temp.array_[i];
    }
}
这是我的复制构造函数;
Vector::Vector(const Vector& rhs)
{
    array_ = new int[rhs.size_];
    size_ = rhs.size_;
    for(unsigned int i = 0; i < rhs.size_; i++)
    {
        array_[i] = rhs.array_[i];
    }
}
最后是main();
 std::cout << \"push_back 5 integers:\\n\";
 for (int i = 0; i < 5; i++)
 {
  a.push_back(i);
   Print(a);
 }

std::cout << \"insert(99, 3):\\n\";
a.insert(99, 3);
Print(a);
std::cout << \"insert(98, 0):\\n\";
a.insert(98, 0);
Print(a);
std::cout << \"insert(97, 6):\\n\";
a.insert(97, 6);
Print(a);
奇怪的是,第一个插入调用(a.insert(99,3))正常工作,第二个调用(a.insert(98,0))崩溃 这是完整的头文件
namespace CS170
 {
    class SubscriptError
    {
     public:
       SubscriptError(int Subscript) : subscript_(Subscript) {};
       int GetSubscript(void) const { return subscript_; }

     private:
    int subscript_;
    };

class Vector
{
public:

    static const int NO_INDEX = -1;

    struct SortResult
    {
        unsigned compares;
        unsigned swaps;
    };

    // Default constructor
    Vector(void);

    // Destructor
    ~Vector();

    // Copy constructor
    Vector(const Vector& rhs);

    // Constructor to create a Vector from an array
    Vector(const int array[], unsigned size);

    // Adds a node to the front of the list
    void push_back(int value);

    // Adds a node to the end of the list
    void push_front(int value);

    // Removes the last element. Does nothing if empty.
    void pop_back(void);

    // Removes the first element. Does nothing if empty.
    void pop_front(void);

    // Inserts a new node at the specified position. Causes an
    // abort() if the position is invalid. (Calls check_bounds)
    void insert(int value, unsigned position) throw(SubscriptError);

    // Removes an element with the specified value (first occurrence)
    void remove(int value);

    // Deletes the underlying array and sets size_ to 0
    void clear(void);

    // Return true if the vector is empty, otherwise, false
    bool empty(void) const;

    // Assignment operator
    Vector& operator=(const Vector& rhs);

    // Concatenates a vector onto the end of this vector.
    Vector& operator+=(const Vector& rhs);

    // Concatenates two Vectors.
    Vector operator+(const Vector& rhs) const;

    // Subscript operators.
    int operator[](unsigned index) const throw(SubscriptError);
    int& operator[](unsigned index) throw(SubscriptError);

    // Returns the number of elements in the vector.
    unsigned size(void) const;

    // Returns the size of the underlying array
    unsigned capacity(void) const;

    // The number of memory allocations that have occurred
    unsigned allocations(void) const;

    // This searches the vector using a binary search instead
    // of a linear search. The data must be sorted. Returns
    // the index. If not found, returns CS170::Vector::NO_INDEX.
    // DO NOT SORT THE DATA IN THIS FUNCTION!!    
    int bsearch(int value) const;

    // Sorts the elements using a selection sort. 
    // Returns the number of swaps/comparisons that occurred.
    SortResult selection_sort(void);

    // Sorts the elements using a bubble_sort.
    // Returns the number of swaps/comparisons that occurred.
    SortResult bubble_sort(void);

    void swap(int &a, int& b);

    void swapv(Vector &other);

    void reverse(void);

    bool operator==(const Vector& rhs) const;

    void shrink_to_fit(void);

private:
    int *array_;        // The dynamically allocated array
    unsigned size_;     // The number of elements in the array
    unsigned capacity_; // The allocated size of the array
    unsigned allocs_;   // Number of allocations (resizes)

    // Private methods...
    void check_bounds(unsigned index) const throw(SubscriptError);
    void grow(void);

    // Other private methods...
};

   }// namespace CS170

        #endif // VECTOR_H
    
已邀请:
您没有(明显地)在
insert()
中调整
array_
的大小。这意味着您将始终在其分配的内存末尾写入一个元素。 复制整个数组(两次)会导致非常昂贵的插入。您要达到什么目的才能达到ѭ6不能完成的目标?     
我认为,当您第一次拨打ѭ5时,会造成损坏。插入元素时,还必须增加分配给成员“ 4”的字节。您只是在增加ѭ9,但是增加实际ѭ4的大小呢? 例如,在您的
insert()
中发生了以下情况:
int size = 5;
int *p = new int[size];
// ... populate p[i] (i = 0 to i = size - 1)
size ++;
p[size - 1] = VALUE; // oops ... incremented \'size\' but before that reallocate to \'p\'
调用后,首先插入您的堆栈将已损坏。所以第二次崩溃了。只需验证相应的代码更改即可。 在旁注, 我觉得你可以写
insert()
,更优化。我觉得不需要暂时复制完整的14英镑。 另外,尝试分配给
array_
的字节数要多于实际需要。这样您就不必多次重新分配 尝试从STL中查看实际ѭ16的源代码,以提高效率。     
在您的插入函数中,您不会为新插入的项目分配内存,并且在第一次插入后,副本ctr尝试读取该行上未分配的内存,这将引发异常。解决方案是最初分配更多的内存(这就是为什么容量用于典型的矢量实现)或在每个插入上增加分配的数组。您必须在两个解决方案上都实现重新分配,但是在第一个解决方案中,调用频率会降低。     

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