clean of unnecessary checks, imports, calls (#7993)

dynamic_programming/fizz_buzz.py

@@ -33,10 +33,9 @@ def fizz_buzz(number: int, iterations: int) -> str:
         ...
     ValueError: iterations must be defined as integers
     """
-
-    if not type(iterations) == int:
+    if not isinstance(iterations, int):
         raise ValueError("iterations must be defined as integers")
-    if not type(number) == int or not number >= 1:
+    if not isinstance(number, int) or not number >= 1:
         raise ValueError(
             """starting number must be
                          and integer and be more than 0"""

dynamic_programming/max_sub_array.py

@@ -62,8 +62,7 @@ def max_sub_array(nums: list[int]) -> int:
     current = 0
     for i in nums:
         current += i
-        if current < 0:
-            current = 0
+        current = max(current, 0)
         best = max(best, current)
     return best