hash table

Popular column stores provide a nested hashmap data model natively.

The Element class extends the Node class, including a collection of Property instances represented in a HashMap structure.

The 52 exercises include using Makefiles to build, while-loop and Boolean expressions, structs and pointers to them, advanced data types and flow control, creative and defensive programming, common undefined behavior, hashmap algorithms, a simple statistics engine, and hacking and improving your server.

3.Try to use the optimized SparseArray, SparseBooleanArray, and LongSparseArray containers instead of HashMap. HashMap allocates an entry object during every mapping which is a memory inefficient action, also the low performance behavior - "autoboxing/unboxing" is spread all over the usage.

In our implementation, data structures such as Vector and Hashmap are exploited for storing routing information.

You can design the application with the fastest algorithms, but a bottleneck like this synchronized "Hashtable" of exchange rates will prevent your application from scaling well, A solution to eliminate the bottleneck could be to use a reader/writer lock that shares the read lock on an unsynchronized 'HashMap" of exchange rates with all threads.