feat(0128_longest-consecutive-sequence): add py3 solution

0128_longest-consecutive-sequence/python3/nlogn.py

@@ -0,0 +1,24 @@
+# Time: O(NlogN)
+# Space: O(1)
+class Solution:
+    def longestConsecutive(self, nums: List[int]) -> int:
+        nums.sort()
+        
+        max_length = 1
+        l = 1
+        
+        # We don't want to go OOB
+        for i in range(0, len(nums) - 1):
+            diff = nums[i + 1] - nums[i]
+            
+            # All good, still consecutive.
+            if diff == 1:
+                l += 1
+                max_length = max(max_length, l)
+            # We skip to next iteration of loop if
+            # item repeats. Otherwise, we reset
+            # running length variable to 1
+            elif diff != 0:
+                l = 1
+        
+        return max_length if len(nums) > 0 else 0