Leetcode sword finger offer jz25 merges two sorted linked lists

  It is known that the two linked lists to be merged are incremental permutations , When merging into a new linked list, we can consider creating a pseudo header

/**
 * struct ListNode {
 *	int val;
 *	struct ListNode *next;
 * };
 *
 * C Language declaration defines global variables. Please add static, Prevent duplicate definitions 
 */

/**
 * 
 * @param pHead1 ListNode class  
 * @param pHead2 ListNode class  
 * @return ListNode class 
 */
struct ListNode* Merge(struct ListNode* pHead1, struct ListNode* pHead2 ) {
    // write code here
    struct ListNode dummy;       // Declare pseudo header pointer 
    struct ListNode * cur=&dummy;  //cur That is, the pseudo header pointer 
    while(pHead1&&pHead2){      // As long as the two linked lists are not empty  , Start looking for 
        if(pHead1->val<=pHead2->val){ // When pHead1 The value is less than pHead2, Link it to the new linked list 
            cur->next=pHead1; 
            pHead1=pHead1->next;  // Then move the linked list back 1
        }
        else
        {
         cur->next=pHead2; 
         pHead2=pHead2->next;  // Ditto and vice versa 
        }
          cur=cur->next;
    }
    cur->next=pHead1==NULL?pHead2:pHead1;   // The list is empty , if 1 Empty rule link 2, Otherwise link 1, Use macro judgment 
    return dummy.next;    Return to the head of the new linked list 
}