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pp:2024:scala:l03 [2024/03/13 18:48]
tudor.condrea Am adaugat un exercitiu pentru reverse 		pp:2024:scala:l03 [2024/03/13 19:27] (current)
tudor.condrea Am modificat increment sa ia predicat si am scos percentage pentru a da mai mult timp la merge sort
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 </​code>​ </​code>​
  
-**3.2.4.** ​Split the list between first names and email domains. What ingredients (auxiliary functions) are necessary? Use either ​a fold or a tail-recursive ​function ​in your implementation. +**(!) 3.2.4.** ​Implement ​a function ​that tokenizes a String split by a given delimiter using ''​foldRight''​. Try to figure out what the accumulator should do.
 <code scala> <code scala>
-def namesEmails(list: List[Str]): List[(Str, Str)] = ???+def mySplit(l: Str, sep: Char): List[Str] = ???
 </​code>​ </​code>​
  
-**3.2.5.** ​Identify ​the list of the employed domain names (e.g. ''​gmail.com''​). Remove duplicates. Use no recursion.+**3.2.5.** ​Implement a function that return ​the domains without ​the dot (ex. ''​gmail''​).
 <code scala> <code scala>
-def domains(l: List[Str]): List[Str] = ??? +def domains(list:​ List[Str]): List[Str] = ???
-</​code>​ +
- +
-**(!) 3.2.6.** In some previous exercise you have, most likely, used already defined function to split the emails. Try implementing a split function using ''​foldRight''​. Try to figure out what the accumulator should do. +
-<code scala> +
-def mySplit(l: Str): List[Str] = ??? +
-</​code>​ +
- +
-**3.2.7.** Generalize the former function for any given character. Use it to implement a function that return the domains without the dot (ex. ''​gmail''​). +
-<code scala> +
-def domain(list: List[Str]): List[Str] = ???+
 </​code>​ </​code>​
  
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 Add this type alias to your code before solving the following exercises. Add this type alias to your code before solving the following exercises.
  
-**3.3.1.** Write a function which adds one point to all students ​which have a passing grade (>= 5), and leaves all other grades unchanged.+**3.3.1.** Write a function which adds one point to all students ​that satisfy ​a given predicate ​(ex: grade >= 5), and leaves all other grades unchanged.
 <code scala> <code scala>
-def increment(g:​ Gradebook): Gradebook =+def increment(g:​ Gradebook, p: (Str, Int) => Boolean): Gradebook =
   g.map(???​) ​   g.map(???​) ​
 </​code>​ </​code>​
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 </​code>​ </​code>​
  
-**3.3.3.** Write a function which takes a gradebook and returns the percentage of failed vs. passed students, as a pair (x,y). +**3.3.3.** Write a function which takes a gradebook and returns the list of names which have passed. Use filter and map from Scala.
-<code scala> +
-def percentage(g:​ Gradebook): (Double,​Double) = ??? +
-</​code>​ +
- +
-**3.3.4.** Write a function which takes a gradebook and returns the list of names which have passed. Use filter and map from Scala.+
 <code scala> <code scala>
 def pass(g: Gradebook): List[Str] = ??? def pass(g: Gradebook): List[Str] = ???
 </​code>​ </​code>​
  
-**3.3.5.** Implement merge-sort (in ascending order) over gradebooks:+**3.3.4.** Implement merge-sort (in ascending order) over gradebooks:
 <code scala> <code scala>
 def mergeSort(l:​ Gradebook): Gradebook = { def mergeSort(l:​ Gradebook): Gradebook = {
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 </​code>​ </​code>​
  
-**3.3.6** Write a function which takes a gradebook and reports all passing students in **descending** order of their grade.+**3.3.5** Write a function which takes a gradebook and reports all passing students in **descending** order of their grade.
 <code scala> <code scala>
 def honorsList(g:​ Gradebook): List[Str] = ??? def honorsList(g:​ Gradebook): List[Str] = ???
 </​code>​ </​code>​