HashMap is one of the most frequently used collection types in Java, it stores key-value pairs. Ideally it expects to use hash table which expects the data access time complexity to be O(1), however, due to hash conflicts, in reality, it uses linked list or red-black tree to store data which makes the worst case time complexity to be O(logn). Although collections are using data structures like arrays and linked lists, unlike arrays, they will dynamically resize when there is not enough space to store data  It involves copying data from old array to the new array which is considered a...