調用包含刪除運算符的析構函數后，C ++程序崩潰

Question

該程序執行直至析構函數的調用，但隨后因錯誤而崩潰：

HEAP CORRUPTION DETECTED ... CRT檢測到應用程序在堆緩沖區結束后寫入了內存。

盡管許多類似的線程都要求使用向量，但我還不知道如何使用向量。 我也認為我應該使用delete []而不是delete 。 但是奇怪的是，當我使用delete []時 ，程序比不使用delete []時更早崩潰了一步（即在顯示矩陣之前）。

我如何擺脫這個錯誤？ 這是否與for循環的使用聯系在一起？

這是代碼：

#include<iostream>

using namespace std;

class Matrix
{
  int n_row, n_col;

  public:

  Matrix(int a = 0, int b = 0)
  {
     n_row = a;
     n_col = b;
  }

  int *m = new int[n_col*n_row];

  ~Matrix()
  {
     cout << "\t deallocating memory\t\n\n";
     delete m;                //ERROR??
  }
 void input_M(int a[], int r, int c);

 void display_M(int a[], int r, int c);

};

void Matrix::input_M(int a[], int r, int c)
{
  cout << "\nEnter elements row-wise\n";
  for (int i = 0; i < r; i++)
      for (int j = 0; j < c; j++)
          cin >> a[i*j + j];
}

void Matrix::display_M(int a[], int r, int c)
{

   for (int i = 0; i < r; i++)
   {
       cout << "\n\n\n";
       for (int j = 0; j < c; j++)
         cout << a[i*j + j] << "\t";
   }
 }


int main()
{
   cout << "  C++ Program to display MATRIX ";

   int r1, r2, c1, c2;

   cout << "\n\n Enter the number of Rows for the First Matrix\t\t:\t";
   cin >> r1;

   cout << "\n\n Enter the number of Columns for the First Matrix\t:\t";
   cin >> c1;

   cout << "\n\n Enter the number of Rows for the Second Matrix\t\t:\t";
   cin >> r2;

   cout << "\n\n Enter the number of Columns for the Second Matrix\t:\t";
   cin >> c2;

   Matrix s1(r1, c1), s2(r2, c2);

   cout << "\nEnter elements for the first Matrix\n";

   s1.input_M(s1.m, r1, c1);       //ALIAS??

   cout << "\nEnter elements for the second Matrix\n";

   s2.input_M(s2.m, r2, c2);
   system("cls");

   cout << "\t\tMatrix 1\n\n";
   s1.display_M(s1.m, r1, c1);

   cout << "\n\n\n\n\t\tMatrix 2\n\n";
   s2.display_M(s2.m, r2, c2);

   system("pause");
   return 0;
 }

Answer 1

要刪除數組，必須使用方括號delete[] m;

例如：

int *m = new int[n_col*n_row];
delete[] m;

int *m = new int; // single element
delete m;

至於您的其他問題，您的程序崩潰的原因是

    Matrix(int a = 0, int b = 0)
    { 
        n_row = a;
        n_col = b;
     }

     // this line is executed before you set n_row and n_col
     int *m = new int[n_col*n_row]; 

修復方法：在使用n_row和m_col創建動態數組之前，請確保已設置它們

Matrix(int a = 0, int b = 0) : n_row(a), n_col(b), m(new int[a*b]) {    }
or
Matrix(int a = 0, int b = 0)
{
    n_row = a;
    n_col = b;
    m = new int[a*b];
}

Answer 2

Yu應該將矩陣分配放入構造函數中：

  Matrix(int a = 0, int b = 0)
  {
     n_row = a;
     n_col = b;
     m = new int[n_col*n_row];
  }

正如您所說，第二件事-您應該使用delete[]