Question

1Suppose you are implementing software to be used in a handheld device that checks whether event attendees are part of a group of people allowed access to a special session at the event. Guests can purchase access to the special session any time up to the instant the event begins, and the device receives updated records to ensure paying guests (only) are allowed in to the special session Would choosing a set data structure to manage the special session guests or a list be more efficient? Explain

2. The methods listed in the Java SE 8 API for the java.util.HashMap class include get(Object key) which returns the value that is associated with the Object in key, or null if there is no association with that key put(K key, V value) which creates an association in the map from the key in key to the value in value. If the key exists already, the value in value is set as the new associated value for key The K and V are generic type labels, since java.util.HashMap is a generic class that declares two generic type parameters <K,V>
Based on your understanding of the design of a map, for each of the following actions 1 through 3 write in words the result of each of the following actions on a HashMap, and write out which associations are currently in the map:
(1) call the put method to make an association between the String “high” and the String “low”

(2) call the put method to make an association between the String “high” and the String “voltage”

(3) call the get method to get the value associated with the String “high”

Answer 1

1. For the above case study, as we need to keep on adding the people names into the list until the concert begins. Thus we will need constant updations thus we need fast time as well as a fast lookup. As when people will enter, we need to check whether the name has booked or not.

Thus these two fast updations are lookup are there fast with O (1) complexity for updating and O(1) for lookup.

But in case of list, it is very slow.

Thus for this purpose, set data structure is best for the implementation for the above case.

Being a Chegg expect I am obliged to do only one question at a time. I hope you understand.

Thanks