Question

An array similar to a phone book has 1000 names arranged as names [0], names[1]....names[999]. Nancy wants to search a name X in this array. Which of the following preconditions must she ensure to perform a binary search?
a. The list has a large number of names.
b. The name X is present in the list.

In addition to the two statements above, which of the following is correct?

a. There should be no duplicates in the list.
b. The names in the list should be alphabetical order.
c. The name X should occur near the middle of the list.

Answer 1

Answer:

b. The names in the list should be in alphabetical order.

Explanation:

A binary search is an algorithm used for searching for an item in a list or array. The algorithm first sorts the data structure into order and then divides it into halves. If the searched item is less than the middle item in the list, then the algorithm searches for the target in the first half, else, in the second half. This reduces the time complexity of the search.