[SOLVED] Java Lab 4

Starting from this week…:

• Use appropriate collections in order to represent data (otherwise: -0.5 points)
• Use Java Stream API in order to perform aggregate operations on data.

  The Student / High School Admission Problem (SAP)

  An instance of SAP involves a set of students and a set of high schools, each student seeking admission to one school, and each school h aving a number of available places (its capacity). Each student ranks some (acceptable) schools in strict order, and each school ranks its applicants in some order. A matching is a set of pairs (student, school) such that each student is assigned to at most one school and the capacities of the schools are not exceeded. A matching is stable if there is no pair (s, h) such that s is assigned to h’ but s prefers h better than h’ and h prefers s better than some of its assigned students. We consider the problem of creating a stable matching between students and schools.

  Example: 4 students S0,S1,S2,S3, 3 high schools H0,H1,H2, capacity(H0)=1, capacity(H1)=2, capacity(H2)=2.

A solution for this example might be: [(S0:H1),(S1:H2),(S2:H1),(S3:H0)] The main specifications of the application are:

Compulsory (1p)

• Create an object-oriented model of the problem. You should have at least the following classes: Student, School and the main class.
• Create all the objects in the example using streams.
• Create a list of students, using LinkedList implementation. Sort the students,

  using a comparator.

• Create a set of schools, using a TreeSet implementation. Make sure

  that School objects are comparable.

• Create two maps (having different implementations) describing the students

  and the school preferences and print them on the screen. Optional (2p)

• Create a class that describes the problem and one that describes a solution (a matching) to this problem.
• Using Java Stream API, write queries that display the students who find acceptable a given list of schools, and the schools that have a given student as their top preference.
• Use a third-party library in order to generate random fake names for students and schools.
• Implement an algorithm for creating a matching, considering that each student has a score obtained at the evaluation exam and the schools rank students based on this score.
• Test your algorithm. Bonus (2p)

• Consider the case in which a school can rank the students based on their specific criteria.
• Implement the Gale Shapley algorithm in order to find a stable matching.
• Consider the case in which preferences are not necessarily strict. Some

  consecutive preferences in an element’s list may form a tie.
  For example S1: H1, [H2,H3] means that S1 prefers H1 over H2 and H3, but H2 and H3 have no precedence one over the other.

• Prove that in the case of SAP with ties, a problem may have multiple stable matchings, not all of the same size.
• Check out other examples of matching in practice. Resources

• Slides
• Aggregate Operations
• The Java Tutorials: Collections ( Know Thy Complexities! )
• Setting the class path
• Creating, Importing, and Configuring Java Projects in Netbeans
• Packaging Programs in JAR Files

  Objectives

• Use various collections and polymorphic algorithms.
• Use Java Stream API.
• Use Optional class and var keyword.
• Understand the notion of CLASSPATH.
• Use external JAR libraries.
• Create a Maven Project.
• Package all project classes as an executable JAR file.