day 4

03.yab

@@ -1,3 +1,5 @@
+dim yabasic 2.90.2, built on x86_64-unknown-linux-gnu
+
 sub getPriority(ch$)
   local a
   a = asc(ch$)

04.pl

@@ -0,0 +1,62 @@
+%! SWI-Prolog version 8.3.29 for x86_64-linux
+%! swipl -s 04.pl -g "sol1(Ans), writeln(Ans)." -t "halt."
+%! swipl -s 04.pl -g "sol2(Ans), writeln(Ans)." -t "halt."
+
+sol1(Answer) :-
+  read_file(String),
+  parse_file(String, Lines),
+  length(Lines, Answer).
+
+read_file(String) :- read_file_to_string("04.txt", String, []).
+
+parse_file(String, Sequences) :-
+  split_string(String, "\n", "", Lines),
+  include(sat, Lines, Sequences).
+
+parse_range(Start, End, String) :-
+  split_string(String, "-", "", [StartStr, EndStr]),
+  number_string(Start, StartStr),
+  number_string(End, EndStr).
+
+range(Set, Start, End) :- setof(A, between(Start, End, A), Set).
+
+meets(A, _, I) :- =(A, I).
+meets(_, B, I) :- =(B, I).
+
+fully_contained(A1, A2, B1, B2) :-
+  range(RangeA, A1, A2),
+  range(RangeB, B1, B2),
+  intersection(RangeA, RangeB, Intersection),
+  meets(RangeA, RangeB, Intersection).
+
+sat(Line) :-
+  split_string(Line, ",", "", [FirstRange, SecondRange]),
+  parse_range(FirstStart, FirstEnd, FirstRange),
+  parse_range(SecondStart, SecondEnd, SecondRange),
+  fully_contained(FirstStart, FirstEnd, SecondStart, SecondEnd).
+
+%%%%%%%%
+
+sol2(Answer) :-
+  read_file(String),
+  parse_file2(String, Lines),
+  length(Lines, Answer).
+
+parse_file2(String, Sequences) :-
+  split_string(String, "\n", "", Lines),
+  include(sat2, Lines, Sequences).
+
+partially_contained(A1, A2, B1, B2) :-
+  range(RangeA, A1, A2),
+  range(RangeB, B1, B2),
+  intersection(RangeA, RangeB, Intersection),
+  not(Intersection == []).
+
+sat2(Line) :-
+  split_string(Line, ",", "", [FirstRange, SecondRange]),
+  parse_range(FirstStart, FirstEnd, FirstRange),
+  parse_range(SecondStart, SecondEnd, SecondRange),
+  partially_contained(FirstStart, FirstEnd, SecondStart, SecondEnd).
+
+
+%! vim: set ft=prolog :