题解 | #合并两个排序的链表#

/**
 * struct ListNode {
 *	int val;
 *	struct ListNode *next;
 * };
 */

/**
 * 
 * @param pHead1 ListNode类 
 * @param pHead2 ListNode类 
 * @return ListNode类
 */
struct ListNode* Merge(struct ListNode* pHead1, struct ListNode* pHead2 ) {
    // write code here
    if(pHead1==NULL)
    return pHead2;
    if(pHead2==NULL)
    return pHead1;
    struct ListNode*n1 = pHead1,*n2 = pHead2;
    struct ListNode*newNode = NULL,*tail = NULL;
    if(n1->val<n2->val)
    {
        newNode = tail = n1;
        n1 = n1->next;
    }
    else{
      newNode = tail = n2;
      n2 = n2->next;
    }
    while(n1&&n2)
    {
         if(n1->val<n2->val)
         {

            tail->next = n1;
            tail = n1;
            n1 = n1->next;
         }
         else {
           tail->next = n2;
           tail = n2;
           n2 = n2->next;
         }

    }
    if(n1)
    tail->next = n1;
    if(n2)
    tail->next = n2;
    return newNode;
}