merge2SortedLists.js

/*
Merge two sorted linked lists and return it as a new sorted list. 
The new list should be made by splicing together the nodes of the first two lists.
Example:
Input: 1->2->4, 1->3->4
Output: 1->1->2->3->4->4*/
/**
 * Definition for singly-linked list.
 * function ListNode(val) {
 *     this.val = val;
 *     this.next = null;
 * }
 */
/**
 * @param {ListNode} l1
 * @param {ListNode} l2
 * @return {ListNode}
 */
var l1 = {
  // 104
  val: 1,
  next: {
    val: 2,
    next: {
      val: 4,
      next: null,
    },
  },
};
var l2 = {
  // 104
  val: 1,
  next: {
    val: 3,
    next: {
      val: 4,
      next: null,
    },
  },
};
console.log(JSON.stringify(l1));
var result = {};
var mergeTwoLists = function (l1, l2) {
  //21
  if (l1 == null) {
    return l2;
  } else if (l2 == null) {
    return l1;
  } else if (l1.val < l2.val) {
    l1.next = mergeTwoLists(l1.next, l2);
    return l1;
  } else {
    l2.next = mergeTwoLists(l1, l2.next);
    return l2;
  }
};

function ListNode(val) {
  this.val = val;
  this.next = null;
}

console.log(mergeTwoLists(l1, l2));