During a binary search, which entries in the array:

a[] = [ 4, 8, 12, 14, 20, 24 ]

are compared to the target when the target is  a) 2;  b) 8;  c) 15.

• Use the textBox for your answer.

Question:

Modify the method inArray() below(note error correction below) so that it returns the index of the first array entry that equals anEntry.  If the array does not contain such an entry, return -1.  You will have to modify binarySearch() also.

• Use the array  a[] = [ 4, 8, 12, 14, 20, 24 ]
• Search for  a) 2 (index = -1);  b) 8 (index = 1);  c)  15 (index = -1)
• Write aa main() to do Question#7.
• Use the method inArray() below.  Note the correction in the parameter list:
       inArray( T[] anArray, T anEntry )
• Use the method binarySearch().

private static >

boolean binarySearch(T[] anArray, int first, int last, T desiredItem)

{

boolean found = false;

int mid = first + (last - first) / 2;

if (first > last)

found = false;

else if (desiredItem.equals(anArray[mid]))

found = true;

else if (desiredItem.compareTo(anArray[mid]) < 0)

found = binarySearch(anArray, first, mid - 1, desiredItem);

else

found = binarySearch(anArray, mid + 1, last, desiredItem);

return found;

}

 

Now the public method inArray appears as follows: 

public static > boolean inArray(T anEntry)

 { 

return binarySearch(anArray, 0, anArray.length − 1, anEntry); 

} // end inArray