Data commit

Task/Partition-function-P/Julia/partition-function-p.julia

@@ -0,0 +1,33 @@
+using Memoize
+
+function partDiffDiff(n::Int)::Int
+    isodd(n) ? (n+1)÷2 : n+1
+end
+
+@memoize function partDiff(n::Int)::Int
+    n<2 ? 1 : partDiff(n-1)+partDiffDiff(n-1)
+end
+
+@memoize function partitionsP(n::Int)
+    T=BigInt
+    if n<2
+        one(T)
+    else
+        psum = zero(T)
+        for i ∈ 1:n
+            pd = partDiff(i)
+            if pd>n
+                break
+            end
+            if ((i-1)%4)<2
+                psum += partitionsP(n-pd)
+            else
+                psum -= partitionsP(n-pd)
+            end
+        end
+        psum
+    end
+end
+
+n=6666
+@time println("p($n) = ", partitionsP(n))