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
 */
#include <stdlib.h>
struct ListNode* Merge(struct ListNode* pHead1, struct ListNode* pHead2 ) {

    struct ListNode* dummy = (struct ListNode*)malloc(sizeof(struct ListNode));
    struct ListNode* current = dummy; 


    while(pHead1 != NULL && pHead2 != NULL)
    {
        if(pHead1->val < pHead2->val)
        {
            current->next = pHead1;
            pHead1=pHead1->next;

        }else {
            current->next = pHead2;
            pHead2 = pHead2->next;
        }
        current = current->next;
    }

    if(NULL != pHead1)
        current->next = pHead1;
    else 
        current->next = pHead2;

    struct ListNode* mergedHead = dummy->next;   
    free(dummy);   

    return mergedHead;
}

核心思想：创建一个虚表头，然后比较两个链表再相互插入