2 files changed, 63 insertions, 3 deletions
diff --git a/src/act4e_solutions/sets_power.py b/src/act4e_solutions/sets_power.py
index 49b4b7b..98d1c69 100644
--- a/src/act4e_solutions/sets_power.py
+++ b/src/act4e_solutions/sets_power.py
@@ -1,11 +1,70 @@
-from typing import Any, overload, TypeVar
+from typing import Any, TypeVar, Iterator, Collection, List
+import itertools
+
+from .sets_representation import MyFiniteSet
+from .sets_properties import SolFiniteSetProperties
 
 import act4e_interfaces as I
 
 X = TypeVar("X")
 
+C = TypeVar("C") # Type of elements of set
+E = MyFiniteSet[C] # Type of sets
+
+
+class MyFiniteSetOfSubsets(I.FiniteSetOfFiniteSubsets[C, E]):
+    # FIXME: _set could be removed
+    _set: I.FiniteSet[C]
+    _subsets: List[I.FiniteSet[C]]
+
+    def __init__(self, theset: I.FiniteSet[C], subsets: Collection[I.FiniteSet[C]]):
+        self._set = theset
+        self._subsets = subsets
+
+        self.fsp = SolFiniteSetProperties()
+        assert(self.fsp.is_subset(s, theset) for s in subsets)
+
+    def size(self) -> int:
+        return len(self._subsets)
+
+    def contains(self, x: E):
+        # print(f"Checking whether {x.elements()} is contained in " +
+        #     str(list(map(lambda l: l.elements(), self._subsets))))
+
+        # Heuristic filter to make it a bit faster
+        same_size = lambda s: s.size() == x.size()
+        for s in filter(same_size, self._subsets):
+            if self.fsp.equal(x, s):
+                # print("it is in there!")
+                return True
+
+        return False
+
+    def elements(self):
+        return self._subsets
+
+    def save(self, h: I.IOHelper, x: E) -> List[E]:
+        # FIXME: I don't think this is correct, same problem as in save
+        return cast(I.ConcreteRepr, x)
+
+    def load(self, h: I.IOHelper, o: I.ConcreteRepr):
+        # FIXME: what the f am I supposed to do here
+        return cast(E, o)
+
+    def contents(self, e: E) -> Iterator[C]:
+        return e.elements()
+
+    def construct(self, elements: Collection[C]) -> E:
+        return MyFiniteSet(elements)
+
 
 class SolFiniteMakePowerSet(I.FiniteMakePowerSet):
     def powerset(self, s: I.FiniteSet[X]) -> I.FiniteSetOfFiniteSubsets[X, Any]:
-        raise NotImplementedError() # implement here
+        subsets = [MyFiniteSet([]), s]
+        for i in range(1, s.size()):
+            # generate all possible subsets with i elements
+            for comb in itertools.combinations(s.elements(), i):
+                subsets.append(MyFiniteSet(list(comb)))
+
+        return MyFiniteSetOfSubsets(s, subsets)
 
diff --git a/src/act4e_solutions/sets_properties.py b/src/act4e_solutions/sets_properties.py
index 2044abd..0d6b3fc 100644
--- a/src/act4e_solutions/sets_properties.py
+++ b/src/act4e_solutions/sets_properties.py
@@ -7,10 +7,11 @@ X = TypeVar("X")
 
 class SolFiniteSetProperties(I.FiniteSetProperties):
     def is_subset(self, a: I.FiniteSet[X], b: I.FiniteSet[X]) -> bool:
+        """ is a a subset of b ? """
         return all([b.contains(e) for e in a.elements()])
 
     def equal(self, a: I.FiniteSet[X], b: I.FiniteSet[X]) -> bool:
-        return self.is_Subset(a, b) and self.is_subset(b, a)
+        return self.is_subset(a, b) and self.is_subset(b, a)
 
     def is_strict_subset(self, a: I.FiniteSet[X], b: I.FiniteSet[X]) -> bool:
         return self.is_subset(a, b) and not self.is_subset(b, a)