Has pair with sum

Author: ebrahimbeiati

Sprint-1/Python/has_pair_with_sum/has_pair_with_sum.py

@@ -7,12 +7,17 @@ def has_pair_with_sum(numbers: List[Number], target_sum: Number) -> bool:
     """
     Find if there is a pair of numbers that sum to a target value.
 
-    Time Complexity:
-    Space Complexity:
-    Optimal time complexity:
+    Time Complexity: O(n^2) because we have two nested loops that iterate through the list of numbers.
+    Space Complexity: O(1)
+    Optimal time complexity: O(n)
+    Explanation: The function checks every possible pair of numbers using two nested loops, resulting in O(n^2) time complexity.
+    Refactor: It uses constant extra space. The optimal solution uses a set to check complements in O(1) time, reducing the overall complexity to O(n).
     """
-    for i in range(len(numbers)):
-        for j in range(i + 1, len(numbers)):
-            if numbers[i] + numbers[j] == target_sum:
-                return True
+    seen = set()
+    for num in numbers:
+        complement = target_sum - num
+        if complement in seen:
+            return True
+        seen.add(num)
+
     return False