private static int BinarySearch <T>(T[] arr, T value, int startIndex, int endIndex)
where T : IComparable <T>
{
Debug.Assert(arr.Length > 0, "Array is empty.");
Debug.Assert(TestAssistant.IsSorted(arr), "Array is not sorted");
while (startIndex <= endIndex)
{
int midIndex = (startIndex + endIndex) / 2;
if (arr[midIndex].Equals(value))
{
return(midIndex);
}
if (arr[midIndex].CompareTo(value) < 0)
{
// Search on the right half
startIndex = midIndex + 1;
}
else
{
// Search on the right half
endIndex = midIndex - 1;
}
}
// Searched value not found
Debug.Assert(Array.Exists(arr, element => element.CompareTo(value) == 0) == false, "Array contains wanted value but search returns -1.");
return(-1);
}
private static int FindMinElementIndex <T>(T[] arr, int startIndex, int endIndex)
where T : IComparable <T>
{
Debug.Assert(arr.Length > 0, "Empty array.");
Debug.Assert(arr.Length <= int.MaxValue, "Length of array is too big.");
Debug.Assert(startIndex >= 0, "Start index is not greater than or equal to 0.");
Debug.Assert(endIndex > 0, "End index is not greater than 0.");
Debug.Assert(startIndex < endIndex, "End index is not greater than start index.");
int minElementIndex = startIndex;
for (int i = startIndex + 1; i <= endIndex; i++)
{
if (arr[i].CompareTo(arr[minElementIndex]) < 0)
{
minElementIndex = i;
}
}
Debug.Assert(TestAssistant.GetMinValue(arr, startIndex, endIndex).CompareTo(arr[minElementIndex]) == 0, "minElementIndex is not the index of min value.");
return(minElementIndex);
}