Question

6.3.1 [10] <§6.2> Consider the following binary search algorithm (a classic divide and conquer algorithm) that searches for a value X in a sorted N-element array A and returns the index of matched entry:

    BinarySearch(A[0..N−1], X) {
       low = 0

       high = N −1
       while (low <= high) {

           mid = (low + high) / 2
           if (A[mid] >X)

              high = mid −1
           else if (A[mid] <X)
              low = mid + 1

           else
              return mid // found

}

       return −1 // not found
    }

Assume that you have Y cores on a multi-core processor to run BinarySearch. Assuming that Y is much smaller than N, express the speedup factor you might expect to obtain for values of Y and N. Plot these on a graph.

Answer 1