Question

Suppose a binary search is to be performed on a table with 50 elements. The maximum number of elements that could be
examined (probes) is:
A. 4 B. 5 C. 6 D. 7

Answer 1

binary search is performed on list of number which are already sorted sample program: first = 0 last = len(alist) - 1 found = false while first < = last and not found midpoint = (first + last)/2 if alist[midpoint] = ite, found = true else: if item < alist[midpoint] last = midpoint - 1 else: first = midpoint + 1 \r\n in binary search maximum probes takes place if the searching element is either 1st element or last element or the element we are searching is not in the list \r\n assume alist of 1 to 50 numbers are sorted. we are searching for 'i' [12345... 20 21 22 23 24 25....40 41 42 43 44...50] first = 0 last = 50 - 1 = 49 midpoint = 0 + 49/2 = 24.5 = 24 (assume floor) alist[midpoint] = 25 notequalto item[1], alist-[27] > item last = midpoint - 1 last = 24 - 1 = 23 materialimplication 1st probe = 25 at array index 24. alist[24] > items first = 0 last = 23 midpoint = 0 + 2/2 = 11.5 = 12