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
        if (pHead1==null)
            return pHead2;
        if (pHead2==null)
            return pHead1;
        ListNode sortedHead = new ListNode(0);
        ListNode p = sortedHead;
        while (pHead1!=null && pHead2!=null){
            if (pHead1.val<=pHead2.val){
                p.next = pHead1;
                pHead1 = pHead1.next;
            }
            else{
                p.next = pHead2;
                pHead2 = pHead2.next;
            }
            p = p.next;
        }
        if (pHead1!=null)
            p.next = pHead1;
        if (pHead2!=null)
            p.next = pHead2;
        return sortedHead.next;
    }
}