c++ - The following prime generator code shows an error when i want prime numbers greater than 1000000.Why? -

the following prime generator code shows error when want prime numbers greater 1000000.why?? @ first seemed occur b'cuz of int changed long error still there.... technically speaking nit error program after running displays message "primegen.exe has stopped working"

#include <iostream> using namespace std; int main() { long int a,c,k,d; k=0; cin>>a; cin>>d; long int b[a]; b[a-1]=0; for(long int i=2;i<=a;i++) {     for(long int j=2;j<=(i/2);j++)     {         c=1;         if ( i%j!=0 )         {             continue;         }             else          {             c=0;             break;         }        }     if (c!=0)         {              b[k]=i;              //++k;         }     else b[k]=0;     ++k;  }  for(long int i=d;i<a;i++)  {      if (b[i]!=0)      {           cout<<b[i]<<"\t";      }           }     cin.ignore();  cin.get();  return 0;  }           

defining static array won't in case. because you're not allowed declare such long static array in c++; might want try

int *b = new int [a]; 

declaring array size dynamically (i.e array size decided @ run time). code should work until variable 'a' exceeds range of int (–2,147,483,648 2,147,483,647).