"Java stream().sorted 或 list.sort() 不会增加时间复杂度吗？"

Question

While making some sortings, some people suggest using stream().sorted<\/code> or list.sort()<\/code> methods in Java to reduce time complexity. However, I think these methods also use some sorting algorithms that has a similar time complexity.

List result = list.stream().sorted((o1, o2)->o1.getItem().getValue().
                                   compareTo(o2.getItem().getValue())).
                                   collect(Collectors.toList());

Answer 1

Sorting algorithms that use nested loops are usually O(n²)<\/code> complexity, due to every iteration of the inner loop occurring for every iteration of the outer loop. Some of these algorithms would be

Answer 2

The very first impotent thing<\/strong> that you have to understand about any kind of algorithm is that just talking<\/strong> about algorithms will not significantly change your knowledge<\/strong> in this area.

Answer 3

The time complexity of these methods is nlog(n) . And it's the best time complexity for sorting an array.