I'm looking for a pre-existing or easy-to-build data structure available in Java, which can do these 2 things efficiently:
- Fetch all the values stored in the collection quickly.
- Iterate over the data structure to fetch each key and its value.
Right now, I'm using a Pair<List, List>.
With this, I can
- Fetch all values stored in collection using pair.getRight() which gives me the entire List. O(n) + cache locality
- Iterate using for(0 to size), pair.getLeft(), pair.getRight() which gives me the key and the value each time. O(n) + some cache locality
This works fine, but it feels ugly to be passing around a pair of 2 lists and having this key value relationship between those lists.
If I just use a regular HashMap, I would have to iterate over the map instead of the list, which is inefficient due to the random memory access.
I could treat combine the key+value into 1 object, and pass around a List instead. This seems cleaner, but at the cost of creating a temporary and unnecessary object.
Can I retain this performance and somehow use a better data structure?
Dictionary<T1,T2>which is Java is I believe a