Refactor Summary Ranges - Leetcode 228.py: Use f-strings and simplify logic

f-strings make the code more readable and stored the len(nums) to avoid constant len() calls.

Author: JohnnyPol

Summary Ranges - Leetcode 228/Summary Ranges - Leetcode 228.py

@@ -2,16 +2,13 @@ class Solution:
     def summaryRanges(self, nums: List[int]) -> List[str]:
         ans = []     
         i = 0 
-        
-        while i < len(nums): 
+        n = len(nums)
+        while i < n: 
             start = nums[i]  
-            while i < len(nums)-1 and nums[i] + 1 == nums[i + 1]: 
+            while i < n - 1 and nums[i] + 1 == nums[i + 1]: 
                 i += 1 
 
-            if start != nums[i]: 
-                ans.append(str(start) + "->" + str(nums[i]))
-            else: 
-                ans.append(str(nums[i]))
+            ans.append(f"{start}->{nums[i]}" if start != nums[i] else f"{nums[i]}")
 
             i += 1