Middle of the Linked List Easy 0 attempts
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Middle of the Linked List

Easy Linked List LeetCode

You get the head of a singly linked list. Return the middle node. If the number of nodes is even, there are two middle positions; return the second of those (the one closer to the tail).

You may return the node itself, not only its value, depending on what your API expects.

Example 1

  • Input: head = [1, 2, 3, 4, 5]
  • Output: [3, 4, 5] (the node with value 3)

Example 2

  • Input: head = [1, 2, 3, 4, 5, 6]
  • Output: [4, 5, 6] (second middle has value 4)

Constraints

  • The list has between 1 and 100 nodes
  • 1 <= Node.val <= 100
Sample Input
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Sample Output
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Constraints
  • 1 to 100 nodes
  • 1 <= Node.val <= 100
Topics
Linked List

Slow and Fast Pointers

function middleNode(head) {
  let slow = head, fast = head;
  while (fast && fast.next) { slow = slow.next; fast = fast.next.next; }
  return slow;
}

Time: O(n) | Space: O(1)

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