feature: four sum revisit

arrays/FourSum.py

@@ -4,7 +4,7 @@
 # O(n^3) time || O(1) space
 def four_sum(self, nums: List[int], target: int) -> List[List[int]]:
     nums.sort()
-    quadruplets = []
+    res = []
     for i in range(len(nums) - 3):
         if i > 0 and nums[i] == nums[i - 1]:
             continue
@@ -15,10 +15,10 @@ def four_sum(self, nums: List[int], target: int) -> List[List[int]]:
 
             low, high = j + 1, len(nums) - 1
             while low < high:
-                sum_ = nums[i] + nums[j] + nums[low] + nums[high]
+                _sum = nums[i] + nums[j] + nums[low] + nums[high]
 
-                if sum_ == target:
-                    quadruplets.append([nums[i], nums[j], nums[low], nums[high]])
+                if _sum == target:
+                    res.append([nums[i], nums[j], nums[low], nums[high]])
                     low, high = low + 1, high - 1
 
                     while low < high and nums[low] == nums[low - 1]:
@@ -27,9 +27,9 @@ def four_sum(self, nums: List[int], target: int) -> List[List[int]]:
                     while low < high and nums[high] == nums[high + 1]:
                         high -= 1
 
-                elif sum_ < target:
+                elif _sum < target:
                     low += 1
                 else:
                     high -= 1
 
-    return quadruplets
+    return res