Pass TestCurrencyOptimizationalphubel-prod

2 files changed, 21 insertions, 3 deletions

diff --git a/Homeworks.md b/Homeworks.md
index e208388..57320d4 100644
--- a/Homeworks.md
+++ b/Homeworks.md
@@ -52,6 +52,6 @@ $ make docker-check
 
 ## Exercises for Nov. 20
 
-- [ ] TestSemiCategoryRepresentation
-- [ ] TestCurrencyOptimization
+- [X] TestSemiCategoryRepresentation
+- [X] TestCurrencyOptimization
 - [ ] TestFinitePosetMinMax
diff --git a/src/act4e_solutions/currency_ex.py b/src/act4e_solutions/currency_ex.py
index c0b6b1b..fbb9775 100644
--- a/src/act4e_solutions/currency_ex.py
+++ b/src/act4e_solutions/currency_ex.py
@@ -9,4 +9,22 @@ class SolCurrencyOptimization(I.CurrencyOptimization):
         amount: float,
         target: str,
     ) -> I.OptimalSolution:
-        pass
+        source, target = available.get_object(source), available.get_object(target)
+
+        results = {}
+        for l in range(available.objects().size() + 1):
+            paths = available.hom(source, target, l)
+            for p in paths.elements():
+                # Allow to go through exchanges only once
+                names = p.label.split(";")
+                if any([names.count(n) > 1 for n in names]):
+                    continue
+
+                rate, commission = p.mordata.rate, p.mordata.commission
+                res = amount * rate - commission
+                results[res] = p
+
+        final = max(results.keys())
+        path = results[final].label.split(";")
+        return I.OptimalSolution(path, final)
+