Search results
Results From The WOW.Com Content Network
Merge sort's main advantages are that it is a stable sort and has excellent worst-case performance. The main disadvantage of merge sort is that it is an out-of-place algorithm, so when operating on arrays, efficient implementations require O ( n ) auxiliary space (vs. O (log n ) for quicksort with in-place partitioning and tail recursion, or O ...
Like the related quicksort sorting algorithm, it was developed by Tony Hoare, and thus is also known as Hoare's selection algorithm. [1] Like quicksort, it is efficient in practice and has good average-case performance, but has poor worst-case performance.
But given a worst-case input, its performance degrades to O(n 2). Also, when implemented with the "shortest first" policy, the worst-case space complexity is instead bounded by O(log(n)). Heapsort has O(n) time when all elements are the same. Heapify takes O(n) time and then removing elements from the heap is O(1) time for each of the n elements.
Best, worst and average case behavior in terms of the size of the list. For typical serial sorting algorithms, good behavior is O(n log n), with parallel sort in O(log 2 n), and bad behavior is O(n 2). Ideal behavior for a serial sort is O(n), but this is not possible in the average case. Optimal parallel sorting is O(log n).
Median of medians finds an approximate median in linear time. Using this approximate median as an improved pivot, the worst-case complexity of quickselect reduces from quadratic to linear, which is also the asymptotically optimal worst-case complexity of any selection algorithm. In other words, the median of medians is an approximate median ...
Running time depends on data ordering. The best case is (() + ) for already sorted data. The worst-case is () for reverse sorted data. In average cases, there are likely to be few heap updates and most input elements are processed with only a single comparison.
Introsort or introspective sort is a hybrid sorting algorithm that provides both fast average performance and (asymptotically) optimal worst-case performance. It begins with quicksort, it switches to heapsort when the recursion depth exceeds a level based on (the logarithm of) the number of elements being sorted and it switches to insertion sort when the number of elements is below some threshold.
Quick sort is the fastest, but it is O(n²) worst case. We must suppose that comb sort is O(n²) worst case too, until somebody proves it otherwise (see the discussion above). Security applications and real time applications are specially sensible to worst case scenarios. That is why libraries should not offer them as all-purpose sorting ...