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Leetcode - 141. Linked List Cycle

· One min read

https://leetcode.com/problems/linked-list-cycle/

Solution 1​

/**
 * Definition for singly-linked list.
 * function ListNode(val) {
 *     this.val = val;
 *     this.next = null;
 * }
 */

/**
 * @param {ListNode} head
 * @return {boolean}
 */
var hasCycle = function (head) {
  if (head === null) {
    return false;
  }

  let curr = head;
  let next = head.next;

  while (next && next.next) {
    curr = curr.next;
    next = next.next.next;

    if (curr === next) {
      return true;
    }
  }

  return false;
};