148. Sort List

Difficulty:
28 / 28 test cases passed.
Runtime: 220 ms
Memory Usage: 37.8 MB

Author: YuriSpiridonov

Medium/148.SortList.py

@@ -0,0 +1,53 @@
+"""
+    Given the head of a linked list, return the list after sorting it in 
+    ascending order.
+
+    Follow up: Can you sort the linked list in O(n logn) time and O(1) memory 
+    (i.e. constant space)?
+
+    Example:
+    nput: head = [4,2,1,3]
+    Output: [1,2,3,4]
+
+    Example:
+    Input: head = [-1,5,3,4,0]
+    Output: [-1,0,3,4,5]
+
+    Example:
+    Input: head = []
+    Output: []
+
+    Constraints:
+        - The number of nodes in the list is in the range [0, 5 * 10**4].
+        - -10**5 <= Node.val <= 10**5
+"""
+#Difficulty:
+#28 / 28 test cases passed.
+#Runtime: 220 ms
+#Memory Usage: 37.8 MB
+
+#Runtime: 220 ms, faster than 66.14% of Python3 online submissions for Sort List.
+#Memory Usage: 37.8 MB, less than 6.25% of Python3 online submissions for Sort List.
+
+# Definition for singly-linked list.
+# class ListNode:
+#     def __init__(self, val=0, next=None):
+#         self.val = val
+#         self.next = next
+
+class Solution:
+    def sortList(self, head: ListNode) -> ListNode:
+        if not head:
+            return
+        current = head
+        values = []
+        while current:
+            values.append(current.val)
+            current = current.next
+        values.sort(reverse=True)
+        head = ListNode(values.pop())
+        node = head
+        while values:
+            node.next = ListNode(values.pop())
+            node = node.next
+        return head