Loop Through a set of Objects

I have a map of key-value pairs of huge size, approxi开发者_运维知识库mately 10^7, and I have to loop through it 15 times a second in order to update its contents Is there any class or structure that offers good complexity and reduces the time needed to loop through?

Currently, I am using TreeMap but the complexity is log n only for contains, put, get and remove. Looping through the elements is of n complexity

Do you know any structure or do you have any idea that may reduce the complexity below n?

---

If you have to arbitrary loop over the entire collection, you will not get better than n. If you have to loop the entire collection, you could use a simple ArrayList. but if you need to access specific data in the collection using a key, TreeMap will be fine.

---

You can't beat the O(n) bound on any sequential (or finitely parallel) computer, if your problem is just to look at all of O(n) values.

If you have a finitely parallel machine and depending on exactly how you're updating the elements, you could achieve speedup. For instance, using CUDA and a GPU or OpenMP/MPI and a cluster/multi-core workstation, you could compute A[i] = A[i]^3 or some such with good speedup. Of course, then there's the question of communication... but this might be something to look at.