solve: mergeKSortedLists

Author: yolophg

merge-k-sorted-lists/yolophg.py

@@ -0,0 +1,22 @@
+# Time Complexity: O(N log N) - collecting all nodes is O(N), sorting is O(N log N)
+# Space Complexity: O(N) - storing all nodes in an array
+
+class Solution:
+    def mergeKLists(self, lists: List[Optional[ListNode]]) -> Optional[ListNode]:
+
+        arr = []
+        
+        # collect all nodes from the linked lists
+        for node in lists:
+            while node:
+                arr.append(node)
+                node = node.next
+
+        # sort all nodes based on their value
+        arr.sort(key=lambda x: x.val)
+
+        # reconnect nodes to form the merged linked list
+        for i in range(len(arr) - 1):
+            arr[i].next = arr[i + 1]
+
+        return arr[0] if arr else None