static void Swap(DuetInTour x, DuetInTour y)
{
var t = x;
x = y;
y = t;
}
///////////////////////////////////
public int Compare(DuetInTour o1, DuetInTour o2)
{
if (o1.mark > o2.mark)
{
return(1);
}
else if (o1.mark < o2.mark)
{
return(-1);
}
return(0);
}