Amazon Interview Question for SDE1s

Country: United States

Comment hidden because of low score. Click to expand.
of 1 vote

I guess you said "min-heap" and in fact it can be either a MIN-heap or MAX-heap or some order sorting order it all depends on your Comparator compareTo function implementation. But in general terms it's modelled internally as a Heap.

- guilhebl April 30, 2017 | Flag Reply
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of 0 vote

It should be correct. This is what the javadoc or PriorityQueue class says:

/**An unbounded priority {@linkplain Queue queue} based on a priority heap.
 * The elements of the priority queue are ordered according to their
 * {@linkplain Comparable natural ordering}, or by a {@link Comparator}
 * provided at queue construction time, depending on which constructor is
 * used.  A priority queue does not permit {@code null} elements.
 * A priority queue relying on natural ordering also does not permit
 * insertion of non-comparable objects (doing so may result in {@code ClassCastException}).*/

- nagib.cs April 25, 2017 | Flag Reply
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of 0 vote

Priority queue represented as a balanced binary heap: the two children of queue[n] are queue[2*n+1] and queue[2*(n+1)]. The priority queue is ordered by comparator, or by the elements' natural ordering, if comparator is null: For each node n in the heap and each descendant d of n, n <= d. The element with the lowest value is in queue[0], assuming the queue is nonempty.

Why did the interviewer say you're wrong?

- respectmyauthoritah April 27, 2017 | Flag Reply

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