diff -r 19b75e899d37 -r 9c03b5e89a2a solutions-resit/resit.scala --- a/solutions-resit/resit.scala Fri Apr 26 17:29:30 2024 +0100 +++ /dev/null Thu Jan 01 00:00:00 1970 +0000 @@ -1,203 +0,0 @@ -// Resit Exam about data-mining a chat log -//========================================= -// -// This coursework is about mining a log of an online chat between 85 -// participants. The log is given as a csv-list in the file -// log.csv. The log is an unordered list containing information which -// message has been sent, by whom, when and in response to which other -// message. Each message has also a number and a unique hash code. -// -// !! For further information abiout the tasks, see: !! -// !! !! -// !! https://nms.kcl.ac.uk/christian.urban/cw-resit.pdf !! - -object Resit { - -import io.Source -import scala.util._ - -//============= -// (1) The function get_csv takes file name as argument. It should read -// the corresponding file and return its content. The content should -// be returned as a list of strings, a string for each line in the -// file. Since the file is a csv-file, the first line (the header) -// should be dropped. Lines are separated by "\n". - - -def get_csv(name: String) : List[String] = ... - -// test cases: -// -// get_csv("log.csv") -// get_csv("log.csv").length // should be 680 - - -//============= -// (2) The function below takes a single line from the csv-file (as -// generated by get_csv) and creates a Rec(ord) data structure. The -// data from the csv-file should be copied as follows: -// -// csv-file Rec data structure -// ----------------------------------- -// counter => num -// id => msg_id -// time_date => date -// name => author -// country => country (should be None if no country is given) -// parent_id => reply_id (should be None if there is no parent) -// msg => msg -// => parent is set to None (will be calculated later) -// => children is set to Nil (will be calculated later) -// -// You should use the function line.split(",").toList to separate -// the items in the csv-line. BE CAREFUL that the message text in -// the last field can contain commas and therefore the split will not -// always result in a list of 7 elements. You need to concatenate -// anything beyond the 7th field into a single string for the field msg. - -case class Rec(num: Int, - msg_id: String, - date: String, - msg: String, - author: String, - country: Option[String], - reply_id : Option[String], - parent: Option[Int] = None, - children: List[Int] = Nil) - - - -def process_line(line: String) : Rec = ... - - -// test cases: -// -// process_line("""0,5ebeb459ac278d01301f1497,2020-05-15T15:25:13.413000,participant34,United Kingdom,5ebea6424923321d63155796,this question please?""") -// -// ==> Rec(0, -// "5ebeb459ac278d01301f1497", -// "2020-05-15T15:25:13.413000", -// "this question please?", -// "participant34", -// Some("United Kingdom"), -// Some("5ebea6424923321d63155796"), -// None, -// List()) -// -// process_line("""1,hash,date,p43,,,foo, bar""") -// -// ==> Rec(1, "hash", "date", "foo, bar", -// "p43", None, None, None, List()) -// -// (Note that in the second test case the message needs to be "foo, bar") - - -//============= -// (3) Each record in the log contains a unique hash code -// identifying each message. Some messages also contain a hash -// code identifying the parent message (to which question they reply). -// The function post_process fills in the information about -// potential children and a potential parent message. -// -// The auxiliary function get_children takes a record e and a -// record list rs as arguments, and returns the list of all direct -// children (which have the hash code of e as reply_id). The list -// of children are returned as a list of nums. -// -// The auxiliary function get_parent returns the number of the -// record corresponding to the reply_id (if there exists one, -// otherwise returns None). - -def get_children(e: Rec, rs: List[Rec]) : List[Int] = ... - -def get_parent(e: Rec, rs: List[Rec]) : Option[Int] = ... - -def post_process(rs: List[Rec]) : List[Rec] = ... - - -// test cases: -// -//val recs = get_csv("log.csv").map(process_line) -// -//post_process(recs)(4).children // List(12) -//post_process(recs)(23).children // List(16,26) -// -//post_process(recs)(8).parent // None -//post_process(recs)(9).parent // Some(7) -//post_process(recs)(16).parent // Some(23) -//post_process(recs)(26).parent // Some(23) - - -//============= -// (4) The next two functions calculate the countries where -// message authors are coming from and how many authors -// come from each country (returned as a Map from countries -// to numbers). In case an author did not specify a country, -// the empty string is returned. - -def get_countries(rs: List[Rec]) : Set[String] = ... - -def get_countries_numbers(rs: List[Rec]) : Map[String, Int] = ... - -// test cases: -// -//val recs = get_csv("log.csv").map(process_line) -// -// get_countries(recs) => -// -// Set("", Poland, Lebanon, Trinidad and -// Tobago, Japan, Spain, Nigeria, Peru, India, Lithuania, Hong -// Kong, Italy, Ireland, Uganda, England, Bangladesh, China, -// Romania, Slovakia, United Kingdom, Norway, Pakistan, Indonesia, -// Malaysia, Turkey, Portugal, Hungary) -// -// get_countries_numbers(recs) => -// -// Map("" -> 4, Poland -> 2, Lebanon -> 1, Trinidad and Tobago -> 2, -// Japan -> 1, Spain -> 1, Nigeria -> 1, Peru -> 1, India -> 6, -// Lithuania -> 1, Hong Kong -> 3, Italy -> 1, Ireland -> 2, Uganda -> 1, -// England -> 4, Bangladesh -> 2, China -> 4, Romania -> 3, -// Slovakia -> 1, United Kingdom -> 34, Norway -> 1, Pakistan -> 2, -// Indonesia -> 2, Malaysia -> 1, Turkey -> 1, Portugal -> 1, -// Hungary -> 2) - - -//============= - -// (5) The function ordered_thread_sizes orders the message threads -// according to how many answers were given for one message (that is -// how many children, grand-children and so on one message has). -// -// The auxiliary function search enumerates all children, -// grand-children and so on for a given record r (including the record -// itself). Search returns the children and so on as a list of Recs. -// -// The function thread_size generates for a record, say r, a pair -// consisting of the number of r and the number of all children as -// produced by search. -// -// The function ordered_thread_sizes orders than the list of pairs -// according to which thread in the chat is the longest. - -def search(r: Rec, rs: List[Rec]) : List[Rec] = ... - -def thread_size(r: Rec, rs: List[Rec]) : (Int, Int) = ... - -def ordered_thread_sizes(rs: List[Rec]) : List[(Int, Int)] = ... - - -// test cases: -// -//val recs_p = post_process(get_csv("log.csv").map(process_line)) -// -//search(recs_p(459), recs_p).map(_.num) -// => List(459, 401, 404, 426, 428, 399, 377, 357, 325, 304) -// -//thread_size(recs_p(459), recs_p) -// => (459,10) -// -//ordered_thread_sizes(recs_p).take(4) -// => List((402,18), (95,12), (488,11), (459,10)) - - -}