refactor(maths): use direct iteration instead of index-based loops in persistence.py

Replace for i in range(len(numbers)) with for number in numbers in both multiplicative_persistence() and additive_persistence(). Direct iteration is more Pythonic and avoids unnecessary index lookups.

Author: fauzan171

maths/persistence.py

@@ -28,8 +28,8 @@ def multiplicative_persistence(num: int) -> int:
         numbers = [int(i) for i in num_string]
 
         total = 1
-        for i in range(len(numbers)):
-            total *= numbers[i]
+        for number in numbers:
+            total *= number
 
         num_string = str(total)
 
@@ -67,8 +67,8 @@ def additive_persistence(num: int) -> int:
         numbers = [int(i) for i in num_string]
 
         total = 0
-        for i in range(len(numbers)):
-            total += numbers[i]
+        for number in numbers:
+            total += number
 
         num_string = str(total)