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) {
        // write code here

        ListNode root = new ListNode(-1);
        ListNode cur = root;

        while (pHead1 != null || pHead2 != null) {
            int v1 = pHead1 == null ? Integer.MAX_VALUE : pHead1.val;
            int v2 = pHead2 == null ? Integer.MAX_VALUE : pHead2.val;

            if (v1 <= v2) {
                pHead1 = pHead1.next;
                cur.next = new ListNode(v1);
            } else {
                pHead2 = pHead2.next;
                cur.next = new ListNode(v2);
            }

            cur = cur.next;
        }
        return root.next;
    }
}