From 729f98e140616b3ad50d65fa0f07bb031725190d Mon Sep 17 00:00:00 2001
From: fredrikr79 <fredrikrobertsen7@gmail.com>
Date: Wed, 5 Nov 2025 08:58:15 +0100
Subject: [PATCH] ex5: task 2.1

---
 assignment5/main.pl  | 43 ++++++++++++++++++++++++++++++-------------
 assignment5/task1.pl | 23 +++++++++++++++++++++++
 2 files changed, 53 insertions(+), 13 deletions(-)
 create mode 100644 assignment5/task1.pl

diff --git a/assignment5/main.pl b/assignment5/main.pl
index e8e2ef4..5ee2ecc 100644
--- a/assignment5/main.pl
+++ b/assignment5/main.pl
@@ -2,22 +2,39 @@
 :- initialization(main).
 
 main :-
-    findall([Ones,Fives,Tens,Twenties], 
-            (payment(25, [coin(Ones,1,11),coin(Fives,5,4),coin(Tens,10,3),coin(Twenties,20,2)]), label([Ones,Fives,Tens,Twenties])), 
+    findall([Path, TotalDistance], 
+            (plan(c1, c2, Path, TotalDistance)), 
             Solutions),
-    forall(member(Sol, Solutions), (write('Solution: '), writeln(Sol))).
+    forall(member([Path, Distance], Solutions), (
+        atomic_list_concat(Path, ' -> ', PathStr),
+        format('Solution: ~w (distance: ~w)~n', [PathStr, Distance])
+    )).
 
-payment(Sum, Coins) :-
-    payment_acc(0, Sum, Coins).
 
-payment_acc(Acc, Sum, []) :-
-    Acc #= Sum.
+distance(c1, c2, 10, 1). distance(c1, c3, 0, 0). distance(c1, c4, 7, 1).
+distance(c1, c5, 5, 1). distance(c2, c3, 4, 1). distance(c2, c4, 12, 1).
+distance(c2, c5, 20, 1). distance(c3, c4, 0, 0). distance(c3, c5, 0, 0).
+distance(c4, c5, 0, 0). distance(c2, c1, 10, 1). distance(c3, c1, 0, 0).
+distance(c4, c1, 7, 1). distance(c5, c1, 5, 1). distance(c3, c2, 4, 1).
+distance(c4, c2, 12, 1). distance(c5, c2, 20, 1). distance(c4, c3, 0, 0).
+distance(c5, c3, 0, 0). distance(c5, c4, 0, 0).
 
-payment_acc(Acc, Sum, [coin(Count, Value, Available)|Tail]) :-
-    Count in 0..Available,
-    NewAcc #= Acc + Count * Value,
-    payment_acc(NewAcc, Sum, Tail).
+% requested arity 4 predicate
+plan(Cabin1, Cabin2, Path, TotalDistance) :-
+    plan(Cabin1, Cabin2, [Cabin1], Path, TotalDistance).
 
-?- payment(25, [coin(Ones,1,11),coin(Fives,5,4),coin(Tens,10,3),coin(Twenties,20,2)]).
-?- payment(25, [coin(Ones,1,11),coin(Fives,5,4),coin(Tens,10,3),coin(Twenties,20,2)]), label([Ones, Fives, Tens, Twenties]).
+% base case
+plan(Cabin1, Cabin2, Visited, Path, Distance) :-
+    not(Cabin1 = Cabin2),
+    distance(Cabin1, Cabin2, Distance, 1),
+    append(Visited, [Cabin2], Path).
+
+% recursive case
+plan(Cabin1, Cabin2, Visited, Path, TotalDistance) :-
+    not(Cabin1 = Cabin2),
+    distance(Cabin1, CabinX, Distance, 1),
+    \+ member(CabinX, Visited),
+    append(Visited, [CabinX], NewVisited),
+    plan(CabinX, Cabin2, NewVisited, Path, SubDistance),
+    TotalDistance is Distance + SubDistance.
 
diff --git a/assignment5/task1.pl b/assignment5/task1.pl
new file mode 100644
index 0000000..e8e2ef4
--- /dev/null
+++ b/assignment5/task1.pl
@@ -0,0 +1,23 @@
+:- use_module(library(clpfd)).
+:- initialization(main).
+
+main :-
+    findall([Ones,Fives,Tens,Twenties], 
+            (payment(25, [coin(Ones,1,11),coin(Fives,5,4),coin(Tens,10,3),coin(Twenties,20,2)]), label([Ones,Fives,Tens,Twenties])), 
+            Solutions),
+    forall(member(Sol, Solutions), (write('Solution: '), writeln(Sol))).
+
+payment(Sum, Coins) :-
+    payment_acc(0, Sum, Coins).
+
+payment_acc(Acc, Sum, []) :-
+    Acc #= Sum.
+
+payment_acc(Acc, Sum, [coin(Count, Value, Available)|Tail]) :-
+    Count in 0..Available,
+    NewAcc #= Acc + Count * Value,
+    payment_acc(NewAcc, Sum, Tail).
+
+?- payment(25, [coin(Ones,1,11),coin(Fives,5,4),coin(Tens,10,3),coin(Twenties,20,2)]).
+?- payment(25, [coin(Ones,1,11),coin(Fives,5,4),coin(Tens,10,3),coin(Twenties,20,2)]), label([Ones, Fives, Tens, Twenties]).
+