public override bool Equals(object obj)
{
SubArrayInfo info = obj as SubArrayInfo;
return(info != null &&
info.StartIndex == StartIndex &&
info.EndIndex == EndIndex);
}
static void Main(string[] args)
{
if (args.Length < 2)
{
Console.WriteLine("Usage: <program> <integer list>");
Console.WriteLine("Example: SubArrayintive 5 6 9 8 9 10");
return;
}
int[] array = new int[args.Length - 1];
// Load integers
for (int i = 1; i < args.Length; i++)
{
if (!int.TryParse(args[i], out array[i - 1]))
{
Console.WriteLine("Invalid argument (" + (i - 1) + ")");
return;
}
}
SubArrayInfo result = getSubArray(array);
if (result == null)
{
Console.WriteLine("It is already sorted");
}
else
{
Console.WriteLine(result.StartIndex + " to " + result.EndIndex);
Console.Write("{ ");
for (int i = result.StartIndex; i < result.EndIndex; i++)
{
Console.Write(array[i] + (i + 1 < result.EndIndex ? ", " : ""));
}
Console.WriteLine(" }");
}
}
/// <summary>
/// Returns the smallest sub-array that, when sorted, makes the entire array to be sorted.
/// </summary>
/// <param name="array">Array to examine</param>
/// <returns>Null if the array is sorted. Else, a SubArrayInfo with the sub-array indexes [start, end)</returns>
public static SubArrayInfo getSubArray(int[] array)
{
SubArrayInfo result = null;
// Searching for first unsorted element
for (int i = 0; i < array.Length - 1; i++)
{
if (array[i] > array[i + 1])
{
result = new SubArrayInfo(i, i + 2);
break;
}
}
// Array is sorted or empty
if (result == null)
{
return(null);
}
// Searching for last unsorted element
for (int i = array.Length - 2; i > result.StartIndex; i--)
{
if (array[i] > array[i + 1])
{
result.EndIndex = i + 2;
break;
}
}
// Serach for min and max values
/* Less efficient
* var subArray = array.Skip(result.StartIndex).Take(result.EndIndex - result.StartIndex);
*
* int min = subArray.Min(),
* max = subArray.Max();
*/
int min = array[result.StartIndex],
max = array[result.StartIndex];
for (int i = result.StartIndex + 1; i < result.EndIndex; i++)
{
if (array[i] < min)
{
min = array[i];
}
if (array[i] > max)
{
max = array[i];
}
}
// Searching for elements before the sub-array that are greater than min
int newIndex = result.StartIndex;
for (int i = 0; i < result.StartIndex; i++)
{
if (array[i] > min)
{
newIndex = i;
break;
}
}
result.StartIndex = newIndex;
// Searching for elements after the sub-array that are lesser than max
newIndex = result.EndIndex;
for (int i = array.Length - 1; i >= result.EndIndex; i--)
{
if (array[i] < max)
{
newIndex = i + 1;
break;
}
}
result.EndIndex = newIndex;
return(result);
}
