Answered step by step
Verified Expert Solution
Link Copied!

Question

1 Approved Answer

An array A of n integers is called semi-sorted if it is increasing until some index and then decreasing afterwards. In other words, there is

An array A of n integers is called semi-sorted if it is increasing until some index and then decreasing afterwards. In other words, there is some index 1 p n such that: A[i] < A[i + 1] for 1 i < p, and A[i] > A[i + 1] for p i < n. Note that in this case, A[p] is the maximum element of A. Give an algorithm with running time O(logn) that nds the maximum element of A, assuming that A is semi-sorted. Prove the correctness of your algorithm as well as do the analysis of the running time. Hint: We can use a modied binary search. The idea is if we pick an index i and compare A[i] with A[i+1] we can determine if i is before the peak (i.e. if i p) or if i is after the peak: if A[i] < A[i+1] then we can conclude that the maximum appears in A[(i + 1),...,n] and if A[i] > A[i + 1] then the maximum is in A[1,...,i]. For correctness, if your algorithm uses a loop, formulate a loop invariant (LI) - what remains to be true throughout all iterations of your loop so that when the loop terminates, LI implies that the maximum element of A is found? If your algorithm is dened by recursion, use Induction to prove the correctness.

Step by Step Solution

There are 3 Steps involved in it

Step: 1

blur-text-image

Get Instant Access to Expert-Tailored Solutions

See step-by-step solutions with expert insights and AI powered tools for academic success

Step: 2

blur-text-image

Step: 3

blur-text-image

Ace Your Homework with AI

Get the answers you need in no time with our AI-driven, step-by-step assistance

Get Started

Recommended Textbook for

Fundamentals Of Database Systems

Authors: Ramez Elmasri, Shamkant B. Navathe

7th Edition Global Edition

1292097612, 978-1292097619

More Books

Students also viewed these Databases questions

Question

List any cash financing product by Meezan Bank in Pakistan

Answered: 1 week ago