[pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

Author: pre-commit-ci[bot]

data_structures/arrays/pairs_with_given_sum.py

@@ -7,10 +7,11 @@
 https://practice.geeksforgeeks.org/problems/count-pairs-with-given-sum5022/0
 """
 
+
 def pairs_with_sum(arr: list[int], req_sum: int) -> int:
     """
     Return the number of pairs with sum equal to req_sum.
-    
+
     >>> pairs_with_sum([1, 5, 7, 1], 6)
     2
     >>> pairs_with_sum([1, 1, 1, 1, 1, 1, 1, 1], 2)
@@ -20,20 +21,21 @@ def pairs_with_sum(arr: list[int], req_sum: int) -> int:
     """
     count = 0
     seen = {}
-    
+
     for num in arr:
         complement = req_sum - num
         if complement in seen:
             count += seen[complement]
-        
+
         if num in seen:
             seen[num] += 1
         else:
             seen[num] = 1
-    
+
     return count
 
+
 if __name__ == "__main__":
     from doctest import testmod
-    testmod()
 
+    testmod()