--- a/progs/roman.scala Wed Mar 20 21:50:20 2019 +0000
+++ b/progs/roman.scala Sat Jun 22 08:39:52 2019 +0100
@@ -1,6 +1,7 @@
-// Part 1 about Roman Numerals
-//=============================
+// Replacement Exam: Scala Part
+//=======================================
+// Roman Digits and Numerals
abstract class RomanDigit
case object I extends RomanDigit
@@ -18,16 +19,25 @@
// As soon as a None is inside the list, the result is None.
// Otherwise produce a list of all Some's appended.
-def optionlist[A](xs: List[Option[A]]): Option[List[A]] =
+//def optionlist[A](xs: List[Option[A]]): Option[List[A]] =
+
+
+// some testcases
+//optionlist(List(Some(1), Some(2), Some(3))) // -> Some(List(1, 2, 3))
+//optionlist(List(Some(1), None, Some(3))) // -> None
+//optionlist(List()) // -> Some(List())
+
+
+
// (2) Write a function first a function that converts a character
// into a roman digit (if possible). Then convert a string into
-// a roman numeral (if possible). If this is not possible, the functions
-// should return None.
+// a roman numeral (if possible). In both cases, if the conversion
+// is not possible, the functions should return None.
-def Char2RomanDigit(c: Char): Option[RomanDigit] =
+//def Char2RomanDigit(c: Char): Option[RomanDigit] =
-def String2RomanNumeral(s: String) : Option[RomanNumeral] =
+//def String2RomanNumeral(s: String) : Option[RomanNumeral] =
// some test cases
@@ -42,108 +52,63 @@
// (3) Write a recursive function RomanNumral2Int that converts a
// RomanNumeral into an integer.
-def RomanNumeral2Int(rs: RomanNumeral): Int =
+//def RomanNumeral2Int(rs: RomanNumeral): Int =
// some test cases
-RomanNumeral2Int(List(I,I,I,I)) // 4
-RomanNumeral2Int(List(I,V)) // 4
-RomanNumeral2Int(List(V,I)) // 6
-RomanNumeral2Int(List(I,X)) // 9
-RomanNumeral2Int(List(M,C,M,L,X,X,I,X)) // 1979
-RomanNumeral2Int(List(M,C,M,X,L,I,V)) // 1944
+//RomanNumeral2Int(List(I,I,I,I)) // 4
+//RomanNumeral2Int(List(I,V)) // 4
+//RomanNumeral2Int(List(V,I)) // 6
+//RomanNumeral2Int(List(I,X)) // 9
+//RomanNumeral2Int(List(M,C,M,L,X,X,I,X)) // 1979
+//RomanNumeral2Int(List(M,C,M,X,L,I,V)) // 1944
+
+
// (4) Write a function that converts a string (containing
-// a roman numeral) into an integer (if possible). If not
+// a roman numeral) into an integer (if possible). If
// this is not possible, the functions should return None.
-def String2Int(s: String): Option[Int] =
-
-// some test cases
-String2Int("IIII") // 4 (though invalid roman numeral)
-String2Int("IV") // 4
-String2Int("VI") // 6
-String2Int("IX") // 9
-String2Int("MCMLXXIX") // 1979
-String2Int("MCMXLIV") // 1944
-String2Int("") // 0
-String2Int("MDCLXI") // 1661
-String2Int("MMMCMXCIX") // 3999
-String2Int("XLVIII") // 48
-String2Int("MMVIII") // 2008
-
-String2Int("MMXI") // 2011
-String2Int("MIM") // 1999
-String2Int("MCMLVI") // 1956
-
-String2Int("III") // 3
-String2Int("XXX") // 30
-String2Int("CCC") // 300
-String2Int("MMM") // 3000
-String2Int("VII") // 7
-String2Int("LXVI") // 66
-String2Int("CL") // 150
-String2Int("MCC") // 1200
-String2Int("IV") // 4
-String2Int("IX") // 9
-String2Int("XC") // 90
-String2Int("MDCLXVI") // 1666
-
-String2Int("VIV") // 9 (but should be written as IX)
-String2Int("IVX") // 14 (also invalid)
-
-// error cases
-String2Int("MC?I")
-String2Int("abc")
-
-
-// (5) The file roman.txt contains a list of roman numerals.
-// Read in these numerals from the file, convert them into
-// integers and then add them all up.
-
-import io.Source
-import scala.util._
-
-// function for reading files:
-// Source.fromFile("file_name")("ISO-8859-9")
-
-def addromanfile(filename: String) =
-
-//test case
-addromanfile("roman.txt")
-
-
-// Part 2 about Validation of Roman Numerals
-//===========================================
-
-// (6) Write a function that validates roman numerals according
-// to the rules given in the CW.
-
-def isValidNumeral(digitList: RomanNumeral): Boolean =
+//def String2Int(s: String): Option[Int] =
// some test cases
-val invalids = List("IXC", "XCX", "IIII", "IIIII", "DD", "VL",
- "MIM", "XXCIII", "LXXIIX", "IIIIX", "IIXX",
- "ICM", "CIM", "VIV", "IVX", "MCMC", "XIIX", "IIXX")
+//String2Int("IIII") // 4 (though invalid roman numeral)
+//String2Int("IV") // 4
+//String2Int("VI") // 6
+//String2Int("IX") // 9
+//String2Int("MCMLXXIX") // 1979
+//String2Int("MCMXLIV") // 1944
+//String2Int("") // 0
+//String2Int("MDCLXI") // 1661
+//String2Int("MMMCMXCIX") // 3999
+//String2Int("XLVIII") // 48
+//String2Int("MMVIII") // 2008
-val valids = List("IV", "VI", "IX", "MCMLXXIX", "MCMXLIV", "", "MDCLXI",
- "MMMCMXCIX", "XLVIII", "MMVIII", "MMXI", "MCMLVI", "III",
- "XXX", "CCC", "MMM", "VII", "LXVI", "CL", "MCC", "XC",
- "MDCLXVI")
-
-// (7) Write a recursive function that converts an Integer into a
-// a roman numeral. The input will be between 0 and 3999.
+//String2Int("MMXI") // 2011
+//String2Int("MIM") // 1999
+//String2Int("MCMLVI") // 1956
-def Int2Roman(n: Int): RomanNumeral =
+//String2Int("III") // 3
+//String2Int("XXX") // 30
+//String2Int("CCC") // 300
+//String2Int("MMM") // 3000
+//String2Int("VII") // 7
+//String2Int("LXVI") // 66
+//String2Int("CL") // 150
+//String2Int("MCC") // 1200
+//String2Int("IV") // 4
+//String2Int("IX") // 9
+//String2Int("XC") // 90
+//String2Int("MDCLXVI") // 1666
-// (8) Write a function that reads a text file containing valid and
-// invalid roman numerals. Convert all valid roman numerals into integers,
-// add them up and produce the result as a roman numeral (using the
-// function in (7)
+//String2Int("VIV") // 9 (but should be written as IX)
+//String2Int("IVX") // 14 (also invalid)
-def addvalidromanfile(filename: String) =
+// error cases
+//String2Int("I I I I")
+//String2Int("MC?I")
+//String2Int("abc")
-// a test case
-//addvalidromanfile("roman2.txt")
+