Algorithms Mergesort

>> YOUR LINK HERE: ___ http://youtube.com/watch?v=HOk0oqZRzz8

This video is part of Professor Frank Stajano's lecture course on Algorithms at the University of Cambridge. • Mergesort is an efficient and easy to describe sorting algorithm: split the given array in half, sort the two halves and then merge the two smaller sorted arrays. We also discuss a non-recursive bottom-up variant. The main drawback of mergesort is the need for some extra workspace. • We show, by solving a recurrence relation, that the time complexity of mergesort is n lg n, which we had previously proved to be a lower bound for comparison sorts (no algorithm can do better than that). This therefore makes mergesort optimal and simultaneously provides an upper bound for the time complexity of comparison sorts (since an n log n algorithm exists, the best algorithm can't do worse than that, otherwise it wouldn't be the best). • If you found this video instructive, give it a thumbs up. Subscribe and hit the notification bell to be notified of new ones. Leave your comments below. • Course web page: • https://www.cl.cam.ac.uk/teaching/cur... • Course handout: • https://www.cl.cam.ac.uk/teaching/202... • My home page: • https://www.cl.cam.ac.uk/~fms27/

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