report/src/task14part2.pl

   1 :- [task14part1].
   2
   3 % Adding a variable for the current path.
   4 extractDiagnoses(HSTree,Diagnoses):-
   5         extractDiagnoses2(HSTree, Diagnoses, []).
   6
   7 % Set path in set and end recursion when leaf had been reached
   8 extractDiagnoses2(leaf, [PathEnd], PathEnd).
   9 % Finished clearing empty node
  10 extractDiagnoses2(node([], []), [], _).
  11 extractDiagnoses2(node([CsHead|CsTail], [CsHeadBranch|CsTailBranches]),
  12                 DiagnosesSet, CurrentPath) :-
  13         % Add new visited conflict item to the visited path
  14         append(CurrentPath, [CsHead], NewPath),
  15         % Recursively collects all paths from the recursive calls into the depth
  16         % and the width and puts them into the DiagnosesSet
  17         append(DepthPaths, WidthPaths, DiagnosesSet),
  18         % Continues into the depth of the branch
  19         extractDiagnoses2(CsHeadBranch,DepthPaths,NewPath),
  20         % Calls on all conflict items in the width of the branch
  21         extractDiagnoses2(node(CsTail, CsTailBranches), WidthPaths, CurrentPath).
  22
  23 % Computes length of smallest diagnosis
  24 getLengthSmallestSet([Diagnosis], DiagnosisLength):-
  25         % Calls length single diagnosis
  26         length(Diagnosis,DiagnosisLength).
  27 getLengthSmallestSet([HeadDiagnosis|RestOfDiagnoses], Minimal):-
  28         % Recursively gets the length of tail.
  29         getLengthSmallestSet(RestOfDiagnoses, RestLength),
  30         % Initialises length of the head diagnosis.
  31         length(HeadDiagnosis,HeadLength),
  32         % Gets minimal length of diagnoses.
  33         Minimal is min(HeadLength, RestLength).
  34
  35 filterLength(X,Y):-
  36         length(Y, LengthY),
  37         %Checks if the set isn't bigger than the smallest set.
  38         X \== LengthY.
  39
  40
  41 getSubsetMinimalDiagnoses(DiagnosesSets, MinimalDiagnosesSets):-
  42         %Gets the length of the smallest set to prune the diagnoses.
  43         %Break so that there will be no backtracking if something goes wrong.
  44         getLengthSmallestSet(DiagnosesSets,Length),!,
  45         % Excludes sets that are bigger than the smallest set
  46         exclude(filterLength(Length), DiagnosesSets, MinimalDiagnosesSets).
  47
  48 % Function that returns minimal hitting sets from a problem.
  49 subsetMinimalDiagnoses(SD, COMP, OBS, HsTree, DiagnosesSets, MinimalDiagnosesSets) :-
  50         % Generate hitting tree.
  51         generateHittingSetTree(SD, COMP, OBS, [], HsTree),
  52         write(HsTree),
  53         % Get diagnoses out of the hitting tree.
  54         extractDiagnoses(HsTree, DiagnosesSets),
  55         write(DiagnosesSets),
  56         % Determine smallest diagnoses.
  57         getSubsetMinimalDiagnoses(DiagnosesSets, MinimalDiagnosesSets).