题解 | #合并两个排序的链表#

/**
 * struct ListNode {
 *	int val;
 *	struct ListNode *next;
 * };
 */
/**
 * 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
 */
 //指向两个链表的指针
struct ListNode* Merge(struct ListNode* pHead1, struct ListNode* pHead2 ) {
    // write code here
    struct ListNode* head ;//创建虚拟头节点
    //当链表为空时
    if (pHead1 == NULL) {
        return pHead2;
    }
    else if (pHead2 == NULL ) {
        return pHead1;
    }
    //递归
    if (pHead1->val < pHead2->val) {
        head = pHead1;
        head->next = Merge(pHead1->next, pHead2);
    }
    else {
        head = pHead2;
        head->next = Merge(pHead2->next, pHead1);
    }
    return head;

    
}