合并两个排序的链表

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* head = (ListNode*)malloc(sizeof(ListNode));
	head->next = NULL;

	ListNode* lastNode= head;
	while(pHead1&&pHead2)
	{
		if(pHead1->val<pHead2->val)
		{
			lastNode->next = pHead1;
			pHead1 = pHead1->next;
		}
		else
		{
			lastNode->next = pHead2;
			pHead2 = pHead2->next;
		}
		lastNode = lastNode->next;
	}

	if(pHead1)
		lastNode->next = pHead1;
	if(pHead2)
		lastNode->next = pHead2;
	return head->next;
}
};