// bubble sort 

 data[20], maxdata;

init()
{ 
  i = 0;
  while(i < maxdata) {
    data[i] = maxdata - i; i = i+1;
  }
}

show()
{ 
  i = 0;
  while(i < maxdata) { print(data[i]," "); i = i+1; }
  print("\n");
}

swap(a,b)
{ 
  t = data[a]; data[a] = data[b]; data[b] = t; 
}

sort()
{ 
  i = 0;
  while(i < maxdata) {
    j = 0;
    while(j < maxdata) {
      if ( data[j+1] < data[j]) swap(j,j+1);
      j = j+1;
    }
    i = i+1;
  }
}

main ()
{
  maxdata = 20;
  init();
  show();
  sort();
  show();
}