What is the time complexity of building a PriorityQueue from a collection?

Question

What is the complexity of the Java PriorityQueue constructor with Collection? I used the constructor:

PriorityQueue(Collection<? extends E> c)

Is complexity O (n) or O (n * log (n))?

Answer 1

The time complexity for initializing a PriorityQueuefrom a collection, even unsorted, is O (n). Internally, it uses a procedure called siftDown()to "heapify" the array in place. (This is also called pushdown in the literature.)

. , - O (log n), n O (n log n). , . (, siftUp().)

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Answer 2

O(log(n)), n O(n).

PriorityQueue(Collection c) , SortedSet, a PriorityQueue Collection -. SortedSet PriorityQueue, O(n) ( ). Collection O(n log(n)).