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 && pHead2 == null){
            return null;
        }
        ListNode flag = new ListNode(0);
        ListNode p,q,temp;
        p=pHead1;
        q=pHead2;
        temp = flag;

        while(p != null && q!=null){
            if(p.val < q.val){
                temp.next = p;
                temp = p;
                p = p.next;
            }else{
                temp.next = q;
                temp = q;
                q= q.next;
            }
        }
        if(p!=null){
            temp.next = p;
            temp = p;
            p = p.next;
        }else{
            temp.next = q;
            temp =q;
            q = q.next;
        }
        return flag.next;

    }
}