题解 | #合并两个排序的链表#

import java.util.*;

/*
 * public class ListNode {
 *   int val;
 *   ListNode next = null;
 *   public ListNode(int val) {
 *     this.val = val;
 *   }
 * }
 */

public class Solution {
    /**
     * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
     *
     *
     * @param pHead1 ListNode类
     * @param pHead2 ListNode类
     * @return ListNode类
     */
    public ListNode Merge (ListNode pHead1, ListNode pHead2) {
        ListNode vNode = new ListNode(-1);
        ListNode head = vNode;
        ListNode p = pHead1;
        ListNode q = pHead2;

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

            } else {
                head.next = q;
                q = q.next;
            }
            head = head.next;
        }
        if (p == null && q != null) {
            head.next = q;
        }
        if (q == null && p != null) {
            head.next = p;
        }
        return vNode.next;
    }
}