From ce51c8748de317c489bf8f422deb954331dc5f04 Mon Sep 17 00:00:00 2001
From: Maxime Vorwerk <maxime@4-werk.com>
Date: Fri, 25 Aug 2023 15:16:02 +0200
Subject: [PATCH] created powerset functions

---
 julia/Powerset.jl | 38 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 38 insertions(+)
 create mode 100644 julia/Powerset.jl

diff --git a/julia/Powerset.jl b/julia/Powerset.jl
new file mode 100644
index 0000000..132df21
--- /dev/null
+++ b/julia/Powerset.jl
@@ -0,0 +1,38 @@
+
+module Powerset
+
+global _calculatedPowerSets = Matrix{Int64}(undef, 1, 0)
+global _grownUntil = 0
+
+function getPowerSet(setSize::Integer)
+    wantedPowerSetSize = 2^setSize
+    if setSize <= _grownUntil
+        return _calculatedPowerSets[1:wantedPowerSetSize, 1:setSize]
+    else
+        currentPowerSetSize = 2^_grownUntil
+        newPowerSets = zeros(Int64, wantedPowerSetSize, setSize)
+        indices = CartesianIndices(_calculatedPowerSets)
+        copyto!(newPowerSets, indices, _calculatedPowerSets, indices)
+        for i ∈ (_grownUntil+1):setSize
+            indicesTarget = CartesianIndices((2^(i-1)+1:2^i, 1:(i-1)))
+            indicesSource = CartesianIndices((1:2^(i-1), 1:(i-1)))
+            copyto!(newPowerSets, indicesTarget, newPowerSets, indicesSource)
+            for j ∈ 1:currentPowerSetSize
+                newPowerSets[currentPowerSetSize + j, i] = 1;
+            end
+            currentPowerSetSize *= 2
+        end
+        _calculatedPowerSets = newPowerSets
+        _grownUntil = setSize
+        return _calculatedPowerSets
+    end
+end
+
+function getPowerSubSet(setSize::Integer, subSetSize::Integer)
+    PowerSet = getPowerSet(setSize)
+    setSizes = dropdim(sum(Powerset, dims = 2), dims = 2)
+
+    return 
+end
+
+end