What action do merge sort, quick sort, and heap sort perform that so radically reduces their complexity? (From O(n2) for the other sorts that we looked at earlierselection sort, bubble sort, and insertion sortto O(n log n) for these)? Hint: they all employ a strategy that has to do with how many things they look at in a pass.

Describe a situation where merge sort would be a better choice for sorting than quick sort.