private static void Adjust (int[] list, int i, int m)
{
 int Temp = list[i];
 int j = i * 2 + 1;
 while (j <= m)
 {
  //more children
  if(j < m)
   if(list[j] < list[j + 1])
    j = j + 1;
  //compare roots and the older children
  if(Temp < list[j])
  {
   list[i] = list[j];
   i = j;
   j = 2 * i + 1;
  }
  else
  {
   j = m + 1;
  }
 }
 list [i] = Temp;
}
public static void HeapSort (int[] list)
{
 //build the initial heap
 for (int i = (list.Length - 1) / 2; i > = 0; i-)
  Adjust (list, i, list.Length - 1);
 
 //swap root node and the last heap node
 for (int i = list.Length - 1; i > = 1; i-)
 {
  int Temp = list [0];
  list [0] = list [i];
  list [i] = Temp;
  Adjust (list, 0, i - 1);
 }
}