21. 合並兩個有序鏈表

兩個有序鏈表合並為一個新的有序鏈表

class Solution {
    public ListNode mergeTwoLists(ListNode l1, ListNode l2) {
        ListNode ans = new ListNode(Integer.MAX_VALUE);
        ListNode p = ans;
        while (l1 != null && l2 != null) {
            if (l1.val < l2.val) {
                p.next = l1;
                l1 = l1.next;
            } else {
                p.next = l2;
                l2 = l2.next;
            }
            p = p.next;
        }
        if (l1 != null) {
            p.next = l1;
        } else if (l2 != null) {
            p.next = l2;
        }
        return ans.next;
    }
}
 

[leetcode] 21. 合並兩個有序鏈表