题解 | #合并两个排序的链表#

/*
public class ListNode {
    int val;
    ListNode next = null;

    ListNode(int val) {
        this.val = val;
    }
}*/
public class Solution {
    public ListNode Merge(ListNode list1,ListNode list2) {
        ListNode i = list1;
        ListNode j = list2;
        ListNode res = new ListNode(-1); //新链表的头的前一个结点
        ListNode node = res;
        while (i != null && j != null) {
            if (i.val - j.val <= 0) {
                node.next = i;
                i = i.next;
            } else {
                node.next = j;
                j = j.next;
            }
            node = node.next;
        }
        ListNode temp;
        temp = i == null ? j : i;
        if (temp != null) {
            node.next = temp;
        }
        return res.next;
    }
}