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) {
	  // 修改边界值
        if (pHead1 == null) return pHead2;
        if (pHead2 == null) return pHead1;
        // write code here
        ListNode result = new ListNode(-22222);
        ListNode cur1 = pHead1;
        ListNode cur2 = pHead2;
        ListNode rescur = result;
        while(cur1 != null && cur2 != null) {
		  // 后插
            if (cur1.val > cur2.val) {
                rescur.next = cur2;
                cur2 = cur2.next;
            } else {
                rescur.next = cur1;
                cur1 = cur1.next;
            }
            rescur = rescur.next;
        }
	  // 把不是空的cur放尾部
        if (cur1 != null) {
            rescur.next = cur1;
        }
        if (cur2 != null) {
            rescur.next = cur2;
        }
        return result.next;
    }
}