190th Commit

README.md

@@ -157,13 +157,14 @@ Ace Coding Interview with 75 Qs
 [933]: ./src/page-9/933.%20Number%20of%20Recent%20Calls/RecentCounter.ts
 [649]: ./src/page-6/649.%20Dota2%20Senate/predictPartyVictory.ts
 
-| Linked List                                   |                 |        |
-| --------------------------------------------- | --------------- | ------ |
-| 2095. Delete the Middle Node of a Linked List | Solution        | Medium |
-| 328. Odd Even Linked List                     | Solution        | Medium |
-| 206. Reverse Linked List                      | [Solution][206] | Easy   |
-| 2130. Maximum Twin Sum of a Linked List       | Solution        | Medium |
-
+| Linked List                                   |                  |        |
+| --------------------------------------------- | ---------------- | ------ |
+| 2095. Delete the Middle Node of a Linked List | [Solution][2095] | Medium |
+| 328. Odd Even Linked List                     | Solution         | 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
 [206]: ./src/page-2/206.%20Reverse%20Linked%20List/reverseList.ts
 
 | Binary Tree - DFS                            |                 |        |

src/page-19/2095. Delete the Middle Node of a Linked List/deleteMiddle.test.ts

@@ -0,0 +1,27 @@
+import { stringify } from 'flatted';
+
+import { generateLinkedList } from '~/utils/linked-list';
+
+import { deleteMiddle } from './deleteMiddle';
+
+describe('2095. Delete the Middle Node of a Linked List', () => {
+  test('deleteMiddle', () => {
+    {
+      const head = generateLinkedList([1, 3, 4, 7, 1, 2, 6]);
+      const expected = generateLinkedList([1, 3, 4, 1, 2, 6]);
+      expect(stringify(deleteMiddle(head))).toBe(stringify(expected));
+    }
+
+    {
+      const head = generateLinkedList([1, 2, 3, 4]);
+      const expected = generateLinkedList([1, 2, 4]);
+      expect(stringify(deleteMiddle(head))).toBe(stringify(expected));
+    }
+
+    {
+      const head = generateLinkedList([2, 1]);
+      const expected = generateLinkedList([2]);
+      expect(stringify(deleteMiddle(head))).toBe(stringify(expected));
+    }
+  });
+});

src/page-19/2095. Delete the Middle Node of a Linked List/deleteMiddle.ts

@@ -0,0 +1,28 @@
+import type { ListNode } from '~/utils/linked-list';
+
+type DeleteMiddle = (head: ListNode | null) => ListNode | null;
+
+/**
+ * Accepted
+ */
+export const deleteMiddle: DeleteMiddle = (head) => {
+  // If the list is empty or has only one node, return null (no middle to remove)
+  if (head === null || head.next === null) return null;
+
+  let slow: ListNode | null = head;
+  let fast: ListNode | null = head;
+  let prev: ListNode | null = null;
+
+  while (fast !== null && fast.next !== null) {
+    prev = slow;
+    slow = slow?.next || null;
+    fast = fast.next.next;
+  }
+
+  // 'slow' is now pointing to the middle node
+  if (prev !== null && slow !== null) {
+    prev.next = slow.next; // Remove the middle node
+  }
+
+  return head;
+};