/**
 * struct ListNode {
 *	int val;
 *	struct ListNode *next;
 *	ListNode(int x) : val(x), next(nullptr) {}
 * };
 */
class Solution {
public:
    /**
     * 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
     */
    ListNode* Merge(ListNode* pHead1, ListNode* pHead2) {
        // write code here
        if(pHead1==nullptr){
            return nullptr;
        }
        ListNode* head=new ListNode(0);
        ListNode* p=head;
        while(pHead1!=nullptr&&pHead2!=nullptr){
            if(pHead1->val>=pHead2->val){
                p->next=pHead2;
                pHead2=pHead2->next;
            }else{
                p->next=pHead1;
                pHead1=pHead1->next;
            }
            p=p->next;
        }
        if(pHead1==nullptr){
          p->next=pHead2;
        }else{
            p->next=pHead1;
        }
        head=head->next;
        return head;
    }
};