// Definition for singly-linked list.
/* struct ListNode {
int val;
struct ListNode *next;
};
*/
struct ListNode* addTwoNumbers(struct ListNode* l1, struct ListNode* l2) {
//分配结果空间
struct ListNode* result = (struct ListNode*)malloc(sizeof(struct ListNode)),*p=l1,*q=l2;
result->val = 0; result->next = NULL;
struct ListNode* head = result;
//设置进位标志
int add = 0;
while(p!=NULL && q!=NULL)
{
if(p->val+q->val >= 10)
{add = 1;}
//
result->val += (p->val + q->val)%10;
p = p->next; q = q->next;
result->next =(struct ListNode*)malloc(sizeof(struct ListNode));
//根据进位值选择下一位的初始值
if(add)
{result->next->val = 1;add = 0;}
else
{result->next->val = 0;}
result->next->next = NULL;
result = result->next;
}
//多出来直接赋值
while(p)
{
result->next =(struct ListNode*)malloc(sizeof(struct ListNode));
result->next->val = 0; result->next->next = NULL;
result = result->next;
result->val = p->val; p = p->next;
}
while(q)
{
result->next =(struct ListNode*)malloc(sizeof(struct ListNode));
result->next->val = 0; result->next->next = NULL;
result = result->next;
result->val = q->val; q = q->next;
}
//如果最后一位为0那么直接释放该空间
if(!result->val) free(result);
return head;
}
但是有个问题,就是为什么加了free(result)会产生runtime error问题