multun · September 9, 2020 09:40 · Sep 9, 2020
diff --git a/ackermann.py b/ackermann.py
@@ -0,0 +1,21 @@
+from functools import lru_cache
+
+
+@lru_cache(maxsize=1024)
+def kn(a, b, order):
+    assert order >= 1
+    if order == 1:
+        return a ** b
+    sub_order = order - 1
+    res = a
+    for i in range(order):
+        res = kn(res, b, sub_order)
+    return res
+
+
+def conway(p, q, r):
+    return kn(p, q, r)
+
+
+def ackermann(m, n):
+    return conway(2, n + 3, m - 2) - 3