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 result = new ListNode(-1);
        ListNode t = result;
        if(pHead1 == null || pHead2 == null) return pHead1 == null ? pHead2: pHead1;
        while(pHead1 != null && pHead2 != null){
            if(pHead1.val <= pHead2.val){
                result.next = pHead1;
                result = result.next;
                pHead1 = pHead1.next;
                result.next = null;
            }else if(pHead2.val < pHead1.val){
                result.next = pHead2;
                result = result.next;
                pHead2 = pHead2.next;
                result.next = null;
            }
        }
        if(pHead1 == null){
            result.next = pHead2;
        }else{
            result.next = pHead1;
        }
        return t.next;
    }
}