public IComparable Select(IComparable [] items, int k)
{
new FYShuffle().Shuffle(items);
int startIndex = 0, endIndex = items.Length - 1;
while (endIndex > startIndex)
{
int j = QuickSort.Partition(items, startIndex, endIndex);
if (j < k)
{
startIndex = j + 1;
}
else if (j > k)
{
endIndex = j - 1;
}
else
{
return(items[k]);
}
}
return(items[k]);
}
//find nth smallest element. The element returned will have n elements smaller or equal to
public static IComparable GetNthElement(IComparable[] inputArray, int n)
{
new Random().Shuffle(inputArray);
int startIndex = 0;
int endIndex = inputArray.Length - 1;
while (endIndex > startIndex)
{
int j = QuickSort.Partition(inputArray, startIndex, endIndex);
if (j == n)
{
return(inputArray[n]);
}
if (j > n)
{
endIndex = j - 1;
}
else
{
startIndex = j + 1;
}
}
return(inputArray[n]);
}
