I had created a c++ program with dynamic 2d array creation it compiles successfully, but when running it shows general proctection fault.the code is given below please tel me where i went wrong? I tried to sent this to djgpp@deloire.com  but it rejects. 
#include<iostream.h>
class dynamic
{
  int **ptr;
  int n;
  public :
  void allocate()
  {
    cout<<"Enter the number of students";
    cin>>n;
   ptr= (int **)new int [n][3];

 }
 void accept()
 {
   cout<<"enter the marks of "<<n<<"students";

   for(int i=0;i<n;i++)
   {
     for(int j=0;j<3;j++)
     cin>>ptr[i][j];
   }

  }
  void display()
  {
    cout<<"the marks of students are"<<endl;
   for(int i=0;i<n;i++)
   {
     for(int j=0;j<3;j++)
     cout<<ptr[i][j];
   }

  }
      
};/* end of class dynamic*/

void main()
{
 dynamic d;
 d.allocate();
 d.accept();
 d.display();
 }
 the program executes upto accept function statement 1 when it do the cin statement in the loop it fails.

This bug tracker is not the right place to learn C++, it's for bugs in the DJGPP library.  Your code is wrong; take the cast off the "new" and heed the warnings thereof, as you're not allocating the memory correctly.