025-合并两个排序的链表.cpp

/*
struct ListNode {
	int val;
	struct ListNode *next;
	ListNode(int x) :
			val(x), next(NULL) {
	}
};*/
class Solution {
public:
    ListNode* Merge(ListNode* pHead1, ListNode* pHead2)
    {
        ListNode* newHead=nullptr;
        if(pHead1==nullptr&&pHead2==nullptr)
            return nullptr;
        if(pHead1==nullptr)
            return pHead2;
        if(pHead2==nullptr)
            return pHead1;
        if(pHead1->val<=pHead2->val){
            newHead=pHead1;
            newHead->next=Merge(pHead1->next,pHead2);
        }else{
            newHead=pHead2;
            newHead->next=Merge(pHead1,pHead2->next);
        }
        return newHead;
    }
};