/**
* 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(list1, list2) {
let c = new ListNode(-1), p = c
while(list1 && list2) {
console.log(list1.val, list2.val)
if (list1.val < list2.val) {
p.next = list1
list1 = list1.next
} else {
p.next = list2
list2 = list2.next
}
p = p.next
}
if (list1) {
p.next = list1
}
if (list2) {
p.next = list2
}
return c.next
// return arr
};
