4 posts tagged with "linkedList"

/**
 * 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;
};

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

/**
 * @param {ListNode} headA
 * @param {ListNode} headB
 * @return {ListNode}
 */
var getIntersectionNode = function (headA, headB) {
  if (!headA || !headB) {
    return null;
  }

  let nodeA = headA;
  let nodeB = headB;

  while (nodeA !== nodeB) {
    nodeA = nodeA.next;
    nodeB = nodeB.next;

    console.log(nodeA, nodeB);

    if (nodeA === nodeB) {
      return nodeA;
    }

    if (!nodeA) {
      nodeA = headB;
    }
    if (!nodeB) {
      nodeB = headA;
    }
  }

  return nodeA;
};

/**
 * Definition for singly-linked list.
 * function ListNode(val, next) {
 *     this.val = (val===undefined ? 0 : val)
 *     this.next = (next===undefined ? null : next)
 * }
 */
/**
 * @param {ListNode} list1
 * @param {ListNode} list2
 * @return {ListNode}
 */
var mergeTwoLists = function (l1, l2) {
  let merge = new ListNode();
  let head = merge;

  while (l1 && l2) {
    if (l1.val < l2.val) {
      merge.next = l1;
      l1 = l1.next;
    } else {
      merge.next = l2;
      l2 = l2.next;
    }
    merge = merge.next;
  }

  if (!l1) merge.next = l2;
  else if (!l2) merge.next = l1;

  return head.next;
};

/**
 * Definition for singly-linked list.
 * function ListNode(val, next) {
 *     this.val = (val===undefined ? 0 : val)
 *     this.next = (next===undefined ? null : next)
 * }
 */
/**
 * @param {ListNode} head
 * @return {ListNode}
 */
var deleteDuplicates = function (head) {
  if (!head) {
    return null;
  }

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

  while (next) {
    if (curr.val === next.val) {
      curr.next = next.next;
    } else {
      curr = curr.next;
    }
    next = next.next;
  }

  return head;
};