191st Commit

README.md

@@ -160,11 +160,12 @@ Ace Coding Interview with 75 Qs
 | Linked List                                   |                  |        |
 | --------------------------------------------- | ---------------- | ------ |
 | 2095. Delete the Middle Node of a Linked List | [Solution][2095] | Medium |
-| 328. Odd Even Linked List                     | Solution         | Medium |
+| 328. Odd Even Linked List                     | [Solution][328]  | Medium |
 | 206. Reverse Linked List                      | [Solution][206]  | Easy   |
 | 2130. Maximum Twin Sum of a Linked List       | Solution         | Medium |
 
 [2095]: ./src/page-19/2095.%20Delete%20the%20Middle%20Node%20of%20a%20Linked%20List/deleteMiddle.ts
+[328]: ./src/page-4/328.%20Odd%20Even%20Linked%20List/oddEvenList.ts
 [206]: ./src/page-2/206.%20Reverse%20Linked%20List/reverseList.ts
 
 | Binary Tree - DFS                            |                 |        |

src/page-4/328. Odd Even Linked List/oddEvenList.test.ts

@@ -0,0 +1,21 @@
+import { stringify } from 'flatted';
+
+import { generateLinkedList } from '~/utils/linked-list';
+
+import { oddEvenList } from './oddEvenList';
+
+describe('328. Odd Even Linked List', () => {
+  test('oddEvenList', () => {
+    {
+      const head = generateLinkedList([1, 2, 3, 4, 5]);
+      const expected = generateLinkedList([1, 3, 5, 2, 4]);
+      expect(stringify(oddEvenList(head))).toBe(stringify(expected));
+    }
+
+    {
+      const head = generateLinkedList([2, 1, 3, 5, 6, 4, 7]);
+      const expected = generateLinkedList([2, 3, 6, 7, 1, 5, 4]);
+      expect(stringify(oddEvenList(head))).toBe(stringify(expected));
+    }
+  });
+});

src/page-4/328. Odd Even Linked List/oddEvenList.ts

@@ -0,0 +1,30 @@
+import type { ListNode } from '~/utils/linked-list';
+
+type OddEvenList = (head: ListNode | null) => ListNode | null;
+
+/**
+ * Accepted
+ */
+export const oddEvenList: OddEvenList = (head) => {
+  // If the list is empty, return it as is
+  if (head === null) return head;
+
+  // Initialize pointers for odd and even nodes
+  let odd = head; // Start odd pointer at the first node
+  let even = head.next; // Start even pointer at the second node
+  const evenHead = even; // Save the start of the even list
+
+  // Traverse the list to rearrange the odd and even nodes
+  while (even !== null && even.next !== null) {
+    odd.next = even.next; // Link current odd node to the next odd node
+    odd = odd.next; // Move the odd pointer to the next odd node
+    even.next = odd.next; // Link current even node to the next even node
+    even = even.next; // Move the even pointer to the next even node
+  }
+
+  // After the loop, connect the end of the odd list to the head of the even list
+  odd.next = evenHead;
+
+  // Return the head of the reordered list
+  return head;
+};