LeetCode, Merge Two Sorted Lists (Java)

leetcode.com/problems/merge-two-sorted-lists/

Merge Two Sorted Lists - LeetCode

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.

제공해주는 ListNode를 이용해서 문제를 풀면 된다.

    class Solution {
        public ListNode mergeTwoLists(ListNode l1, ListNode l2) {
            ListNode head = new ListNode();
            ListNode p = head;

            ListNode p1 = l1;
            ListNode p2 = l2;

            while (p1 != null && p2 != null) {
                if (p1.val < p2.val) {
                    p.next = p1;
                    p1 = p1.next;
                } else {
                    p.next = p2;
                    p2 = p2.next;
                }

                p = p.next;
            }

            if (p1 != null) {
                p.next = p1;
            }

            if (p2 != null) {
                p.next = p2;
            }

            return head.next;
        }
    }