Merge pull request #11939 from adamcrussell/challenge-318

initial commit of Prolog solutions

3 files changed, 78 insertions, 0 deletions

diff --git a/challenge-318/adam-russell/blog1.txt b/challenge-318/adam-russell/blog1.txt
new file mode 100644
index 0000000000..0f80551133
--- /dev/null
+++ b/challenge-318/adam-russell/blog1.txt
@@ -0,0 +1 @@
+http://rabbitfarm.com/cgi-bin/blosxom/prolog/2025/04/27
diff --git a/challenge-318/adam-russell/prolog/ch-1.p b/challenge-318/adam-russell/prolog/ch-1.p
new file mode 100644
index 0000000000..2584a2dceb
--- /dev/null
+++ b/challenge-318/adam-russell/prolog/ch-1.p
@@ -0,0 +1,21 @@
+
+  
+  group(Letters, Letter, Group):-
+      length(Letters, LengthLetters),
+      delete(Letters, Letter, Deleted),
+      length(Deleted, LengthDeleted),
+      Difference is LengthLetters - LengthDeleted,
+      Difference >= 3,
+      length(G1, Difference),
+      maplist(=(Letter), G1),
+      append(G1, _, G2),
+      append(_, G2, Letters),
+      atom_codes(Group, G1).
+  group(_, _, nil).
+
+  
+  groupings(Word, Groupings):-
+      sort(Word, UniqueLetters),
+      maplist(group(Word), UniqueLetters, Groups),
+      delete(Groups, nil, Groupings).
+ 
diff --git a/challenge-318/adam-russell/prolog/ch-2.p b/challenge-318/adam-russell/prolog/ch-2.p
new file mode 100644
index 0000000000..58d9e91127
--- /dev/null
+++ b/challenge-318/adam-russell/prolog/ch-2.p
@@ -0,0 +1,56 @@
+
+  
+  reverse_equals(List1, List2):-
+      
+  subtract(List1, List2, []),
+
+      
+      length(List1, Length),
+      findall(I, (
+          between(1, Length, I),
+          nth(I, List1, C1),
+          nth(I, List2, C2),
+          \+ C1 = C2
+      ), DifferenceIndices),
+
+      
+      length(DifferenceIndices, NumberDifferences),
+      NumberDifferences > 0,
+      nth(1, DifferenceIndices, FirstIndex),
+      last(DifferenceIndices, LastIndex),
+      findall(E, (
+          between(FirstIndex, LastIndex, I),
+          nth(I, List1, E)
+      ), SubList1),
+      findall(E, (
+          between(FirstIndex, LastIndex, I),
+          nth(I, List2, E)
+      ), SubList2),  
+
+      
+      reverse(SubList1, Reverse1),
+      reverse(SubList2, Reverse2),
+      append(SubList1, Suffix1, S1),
+      append(SubList2, Suffix2, S2),  
+      append(Reverse1, Suffix1, S3),
+      append(Reverse2, Suffix2, S4),     
+      append(Prefix1, S1, List1),
+      append(Prefix2, S2, List2),
+      (append(Prefix1, S3, List2); append(Prefix2, S4, List1))
+.
+  reverse_equals(List1, List2):-
+      
+  subtract(List1, List2, []),
+
+      
+      length(List1, Length),
+      findall(I, (
+          between(1, Length, I),
+          nth(I, List1, C1),
+          nth(I, List2, C2),
+          \+ C1 = C2
+      ), DifferenceIndices),
+
+      length(DifferenceIndices, NumberDifferences),
+      NumberDifferences = 0.
+