CSCI 570 - Fall 2016 - HW 5September 23, 20161. Solve the following recurrences by giving tight Θ-notation bounds in termsof n for sufficiently large n. Assume that T represents the running time ofan algorithm, i.e. T (n) is positive and non-decreasing function of n andfor small constants c independent of n, T (c) is also a constant independentof n.(a) T(n) = 4T(n/2) + n2log n(b) T(n) = 8T(n/6) + n log n(c) T(n) = 2T(√n) + log n2. Solve Kleinberg and Tardos, Chapter 5, Exercise 3.3. Solve Kleinberg and Tardos, Chapter 5, Exercise 5.4. Assume that you have a black-box that can multiply two integers. De-scribe an algorithm that when given an n-bit positive integer a and aninteger x, computes xawith at most O(n) calls to the black-box.5. Consider the following algorithm StrangeSort which sorts n distinct itemsin a list A.(a) If n ≤ 1, return A unchanged.(b) For each item x ∈ A, scan A and count how many other items in Aare less than x.(c) Put the items with count less than n/2 in a list B.(d) Put the other items in a list C.(e) Recursively sort lists B and C using StrangeSort.(f) Append the sorted list C to the sorted list B and return the result.Formulate a recurrence relation for the running time T (n) of StrangeSorton a input list of size n. Solve this recurrence to get the best possible O(.)bound on T (n) .6. Consider an array A of n numbers with the assurance that n > 2, A[1] ≥A[2] and A[n] ≥ A[n −1]. An index i is said to be a local minimum of thearray A if it satisfies 1 < i < n, A[i − 1] ≥ A[i] and A[i + 1] ≥ A[i].1(a) Prove that there always exists a local minimum for A.(b) Design an algorithm to compute a local minimum of A. Your al-gorithm is allowed to make at most O(log n) pairwise comparisonsbetween elements of A.7. Given a sorted array of n integers that has been rotated an unknownnumber of times, give an O(log n) algorithm that finds an element in thearray. An example of array rotation is as follows: original sorted arrayA = [1, 3, 5, 7, 11], after first rotation A0= [3, 5, 7, 11, 1], after secondrotation A00= [5, 7, 11, 1, 3
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