16合并两个排序的链表

题目描述

输入两个单调递增的链表，输出两个链表合成后的链表，当然我们需要合成后的链表满足单调不减规则。

Java实现

class ListNode {
    int val;
    ListNode next;

    ListNode(int val) {
        this.val = val;
    }
}

public class Solution {
    public ListNode Merge(ListNode list1, ListNode list2) {
        ListNode dummyHead = new ListNode(0);
        ListNode curr = dummyHead;
        ListNode p = list1, q = list2;

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

        if (p != null)
            curr.next = p;

        if (q != null)
            curr.next = q;

        return dummyHead.next;
    }
}