题解 | #合并两个排序的链表#

这个解法的关键是创建链表头
没啥好说的，很简单。。

/*
struct ListNode {
    int val;
    struct ListNode *next;
    ListNode(int x) :
            val(x), next(NULL) {
    }
};*/
class Solution {
public:
    ListNode* Merge(ListNode* pHead1, ListNode* pHead2) {
        if(pHead1 == NULL ) return pHead2;
        if(pHead2 == NULL ) return pHead1;
        ListNode* newNode = new ListNode(-1);

        ListNode* curNode =newNode;
        while(pHead1 != NULL && pHead2 != NULL){
            if(pHead1->val <= pHead2->val){
                curNode->next = pHead1;
                pHead1 = pHead1->next;
            }
            else{
                curNode->next = pHead2;
                pHead2 = pHead2->next;
            }
            curNode = curNode->next;
        }
        if(pHead1 != NULL)    curNode->next = pHead1;
        else curNode->next = pHead2;
        return newNode->next;
    }
};