public static void Test()
{
var obj = new QuickSelect();
// int[] array = new[] {5, 9, 1, 7, 2, 4, 5};
int[] array = new[] { 1, 9, 1, 20, 2, 3, 2 };
obj.DoSelect(array, 0, array.Length - 1, array.Length / 2);
Utils.DumpArray(array);
}