// MergeSort array of strings.
public String[] MergeSortStrings(String[] unsortedArray, int numOfAllElementsToSort)
{
// Send initial progress report.
if (sortMethodCalls == 0)
{
sortEventsRaised++;
MergeSortProgress?.Invoke(this, sortMethodCalls, numOfAllElementsToSort);
}
// Increase global method calls counter.
sortMethodCalls++;
// Frequency of progress reports.
int frequency = numOfAllElementsToSort / 5;
if (frequency <= 0)
{
frequency = 1;
}
// Send progression reports.
if (sortMethodCalls % frequency == 0)
{
sortEventsRaised++;
MergeSortProgress?.Invoke(this, sortMethodCalls, numOfAllElementsToSort);
}
if (unsortedArray.Length < 2)
{
// Array is sorted.
return(unsortedArray);
}
else
{
int middle = unsortedArray.Length / 2;
String[] left = unsortedArray.Take(middle).ToArray();
String[] right = unsortedArray.Skip(middle).ToArray();
left = MergeSortStrings(left, numOfAllElementsToSort);
right = MergeSortStrings(right, numOfAllElementsToSort);
return(MergeStringArrays(left, right, numOfAllElementsToSort));
}
}
// Helper for MergeSort array of strings.
private String[] MergeStringArrays(String[] left, String[] right, int numOfAllElementsToSort)
{
// Increase global method calls counter.
sortMethodCalls++;
String[] sortedArray = new String[left.Length + right.Length];
if (left.Length == 1 && right.Length == 1)
{
if (CompareStrings(left[0], right[0]) <= 0)
{
sortedArray[0] = left[0];
sortedArray[1] = right[0];
}
else
{
sortedArray[0] = right[0];
sortedArray[1] = left[0];
}
}
else
{
int left_i = 0;
int right_i = 0;
while (left_i < left.Length && right_i < right.Length)
{
int index = Array.IndexOf(sortedArray, null);
if (CompareStrings(left[left_i], right[right_i]) <= 0)
{
sortedArray[index] = left[left_i];
left_i++;
}
else
{
sortedArray[index] = right[right_i];
right_i++;
}
}
if (left_i < left.Length)
{
while (left_i < left.Length)
{
int index = Array.IndexOf(sortedArray, null);
sortedArray[index] = left[left_i];
left_i++;
}
}
if (right_i < right.Length)
{
while (right_i < right.Length)
{
int index = Array.IndexOf(sortedArray, null);
sortedArray[index] = right[right_i];
right_i++;
}
}
}
// Frequency of progress reports.
int frequency = numOfAllElementsToSort / 5;
if (frequency <= 0)
{
frequency = 1;
}
// Used to make certain of sending final progression report.
int lastCall;
if (numOfAllElementsToSort < 2)
{
lastCall = 1;
}
else if (numOfAllElementsToSort > 2)
{
lastCall = numOfAllElementsToSort * 2 + (numOfAllElementsToSort - 2);
}
else
{
lastCall = numOfAllElementsToSort * 2;
}
// Send progression reports.
if (sortMethodCalls % frequency == 0 || sortMethodCalls == lastCall)
{
sortEventsRaised++;
MergeSortProgress?.Invoke(this, sortMethodCalls, numOfAllElementsToSort);
}
return(sortedArray);
}
