コード例 #1
0
    private static int BinarySearch <T>(T[] arr, T value, int startIndex, int endIndex)
        where T : IComparable <T>
    {
        Debug.Assert(startIndex < endIndex, "Starting index was larger than ending index");

        while (startIndex <= endIndex)
        {
            Debug.Assert(startIndex < arr.Length, "Start index became larger than array length.");
            Debug.Assert(endIndex >= 0, "End index became less than zero");

            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(AssertionUtilities.IsNotInArray(value, arr), "The value was in the array.");
        return(-1);
    }