剑指Offer_编程题_16

题目描述

输入两个单调递增的链表，输出两个链表合成后的链表，当然我们需要合成后的链表满足单调不减规则。

/*
struct ListNode {
	int val;
	struct ListNode *next;
	ListNode(int x) :
			val(x), next(NULL) {
	}
};*/
class Solution {
public:
    ListNode* Merge(ListNode* pHead1, ListNode* pHead2)
    {
        ListNode* h1 = new ListNode(0);
        ListNode* h2 = h1;
        while(pHead1 != NULL && pHead2 != NULL){
            if(pHead1->val < pHead2->val){
                h1->next = pHead1;
                pHead1=pHead1->next;
                h1 = h1->next;
            }else if(pHead1->val >= pHead2->val){
                h1->next = pHead2;
                pHead2=pHead2->next;
                h1 = h1->next;
            }
            h1->next = NULL;
        }
        if(pHead1){
            h1->next = pHead1;
        }else if(pHead2){
            h1->next = pHead2;
        }
        return h2->next;
    }
};