leetcode

commit 08e6a1004a6aae8e31d958816b2ad56803f4b914
parent c23e5e8c6718f0be24e9a4a0ab458014ddcd600e
Author: AndrewLockVI <andrewlaack1@gmail.com>
Date:   Mon, 15 May 2023 12:56:58 -0500

Completed reorder list problem using dart

Diffstat:
A
reorder-list/reorder-list.dart
 | 
36
++++++++++++++++++++++++++++++++++++

1 file changed, 36 insertions(+), 0 deletions(-)
diff --git a/reorder-list/reorder-list.dart b/reorder-list/reorder-list.dart
@@ -0,0 +1,36 @@
+//Given a singly linked list return the list where the order is
+//L1,Ln,L2,Ln-1 and so on where n is the length of the list.
+//The time complexity of this code is O(n) where n is the length of the list.
+//My solution first creates a list of the linked list then orders it properly,
+//and it finally sets the next of each node to the proper node.
+//Time: 271ms Beats: 100%
+//Memory: 148.2MB Beats: 66.67%
+class Solution {
+  void reorderList(ListNode? head) {
+      ListNode? itr = head;
+      List<ListNode?> vals = [];
+      while(itr != null){
+          vals.add(itr);
+          itr = itr.next;
+      }
+      List<ListNode?> return_list = [];
+      return_list.add(vals[0]);
+
+      for(int i = 0 ; return_list.length < vals.length + 1; ++i){
+        return_list.add(vals[i]);
+        return_list.add(vals[vals.length - 1 - i]);
+      }
+
+      for(int i = 0 ; i < return_list.length - 1 ; ++i){
+        return_list[i]?.next = return_list[i + 1];
+      }
+      if(vals.length % 2 == 1){
+        return_list[return_list.length - 2]?.next = null;
+
+      }
+      else{
+        return_list[return_list.length - 1]?.next = null;
+      }
+
+  }
+}