Estimate how many searches will be needed to justify time spent on presorting an array of 103 elements if sorting is done by mergesort and searching is done by binary search. (You may assume that all searches are for elements known to be in the array.) What about an array of 106 elements?

Implement a document scanning function wordcountengine, which receives a string document and returns a list of all unique words in it and their number of occurrences, sorted by the number of occurrences in a descending order. if two or more words have the same count, they should be sorted according to their order in the original sentence. assume that all letters are in english alphabet. you function should be case-insensitive, so for instance, the words “perfect” and “perfect” should be considered the same word.