DRM Messages

drmmessages.py

@@ -0,0 +1,23 @@
+def sumOfValuesOfCharacters(s: str) -> int:
+    return sum([ord(c) - 65 for c in s])
+
+
+def rotateString(s: str, r: int) -> str:
+    return "".join([chr(((ord(c) - 65 + r) % 26) + 65) for c in s])
+
+
+def mergeStrings(a: str, b: str) -> str:
+    return "".join(
+        [rotateString(ca, sumOfValuesOfCharacters(cb)) for ca, cb in zip(a, b)]
+    )
+
+
+def decrypt(drmmessage):
+    half = len(drmmessage) // 2
+    a, b = drmmessage[:half], drmmessage[half:]
+    rota = rotateString(a, sumOfValuesOfCharacters(a))
+    rotb = rotateString(b, sumOfValuesOfCharacters(b))
+    return mergeStrings(rota, rotb)
+
+
+print(decrypt(input()))