题解 | 合并两群能量值

1. 递归写法不再展示。
2. 利用引用交换实现代码统一。

import java.util.*;

public class Solution {
    public ListNode mergeEnergyValues (ListNode l1, ListNode l2) {
        if (l1 == null) {
            return l2;
        }
        if (l2 == null) {
            return l1;
        }
        ListNode guard = new ListNode(0);
        ListNode t = guard;
        while (l1 != null && l2 != null) {
            if (l2.val > l1.val) {
                final ListNode tmp = l1;
                l1 = l2;
                l2 = tmp;
            }
            t.next= l1;
            l1 = l1.next;
            t = t.next;
        }
        t.next = l2;
        return guard.next;
    }
}