Merge branch 'main' of https://github.com/ShrujanKotturi/leetcode into main

Author: ShrujanKotturi

Diff for: python/18-4Sum.py

@@ -0,0 +1,26 @@
+class Solution:
+    def fourSum(self, nums, target):
+        def findNsum(l, r, target, N, result, results):
+            if r-l+1 < N or N < 2 or target < nums[l]*N or target > nums[r]*N:  
+                return
+            if N == 2: 
+                while l < r:
+                    s = nums[l] + nums[r]
+                    if s == target:
+                        results.append(result + [nums[l], nums[r]])
+                        l += 1
+                        while l < r and nums[l] == nums[l-1]:
+                            l += 1
+                    elif s < target:
+                        l += 1
+                    else:
+                        r -= 1
+            else:
+                for i in range(l, r+1):
+                    if i == l or (i > l and nums[i-1] != nums[i]):
+                        findNsum(i+1, r, target-nums[i], N-1, result+[nums[i]], results)
+
+        nums.sort()
+        results = []
+        findNsum(0, len(nums)-1, target, 4, [], results)
+        return results