Menu driven pattern program

#include<iostream.h>
#include<conio.h>
#include<process.h>

void ltrsPtrn(int n)
{
  int i, j;
  for(i=0; i<n; i++)
  {
    for(j=0; j<=i; j++)
    {
      cout<<char(65+j);
    }
    cout<<'\n';
  }
}
void dgtsPtrn(int n)
{
  int i, j;
  for(i=0; i<n; i++)
  {
    for(j=0; j<=i; j++)
    {
      cout<<j+1;
    }
    cout<<'\n';
  }
}

void starPtrn(int n)
{
  int i, j;
  for(i=0; i<n; i++)
  {
    for(j=0; j<=i; j++)
    {
      cout<<'*';
    }
    cout<<'\n';
  }
}

void rvrsPtrn(int n)
{
  int i, j;
  for(i=0; i<n; i++)
  {
    for(j=n-i; j>0; j--)
    {
      cout<<'*';
    }
    cout<<'\n';
  }
}

void main()
{
  clrscr();
  int n, r;
  char ch;
  cout<<"Enter a number. ";
  cin>>r;
  do
  {
    cout<<"\n\tMenu.";
    cout<<"\n1. Alphabetical Pattern\n2. Digits Pattern\n3. Star Pattern\n4. Reverse star Pattern\n5. Exit.\nEnter your choice. ";
    cin>>n;

    switch(n)
    {
      case 1: ltrsPtrn(r); break;
      case 2: dgtsPtrn(r); break;
      case 3: starPtrn(r); break;
      case 4: rvrsPtrn(r); break;
      case 5: exit(0); break;
      default: cout<<"\nPlease enter valid choice {1-5}!";
    }

    cout<<"Want to run again? (Yes/No)";
    cin>>ch;
  } while( (ch=='Y') || (ch=='y') );

  getch();
}