# What are the disadvantages of Fibonacci Heaps?

A Fibonacci heap is a data structure for priority queue / heap operations. It seems to have the best complexity for all operations:

Since it has the best performance, why not use it everywhere? What are the disadvantages of it?

• Those are asymptotic orders of growth of the number of operations (some of them of the expected value of the number of steps) in terms of the size of the input. They are not exact number of operations, or even estimations that give information for all values of $n$. From that information alone you cannot deduce that for a particular value of $n$ or for a fixed collection of values of $n$ one is faster than the other.
– plop
Jul 10, 2020 at 15:37

$$O(1)$$ merely means that no matter how large your heap grows, the operation will always take roughly the same time to execute. It doesn't mean "the fastest".