friendList

Language$/$Type: $,$ Java TreeMap collections compound collections file input

Related Links: $,$ String TreeMap File Scanner

Write a method named friendList that accepts a file name as a parameter and reads friend relationships from a file and stores them into a compound collection that is returned. You should create a map where each key is a person's name from the file, and the value associated with that key is a setof all friends of that person. Friendships are bi$-$directional: if Marty is friends with Danielle, Danielle is friends with Marty.

The file contains one friend relationship per line, consisting of two names. The names are separated by a single space. You may assume that the file exists and is in a valid proper format. If a file named buddies. txt looks like this:

Marty Cynthia

Danielle Marty

Then the call of friendList $("$buddies$.$txt$")$ should return a map with the following contents:

Cynthia Marty