You are given two linked lists representing two non-negative numbers. The digits are stored in reverse order and each of their nodes contain a single digit. Add the two numbers and return it as a linked list.
Input: (2 -> 4 -> 3) + (5 -> 6 -> 4)
Output: 7 -> 0 -> 8
这道题主要容易忽略的几点在:
1 , 链表 L1 和 L2 不一定是一样长的 ,设计的程序必须考虑到.
2, 这道题的问题主要不光要考虑到时间复杂度(感觉都能过),还要注意要空间复杂度(不要浪费空间).
其他应该不是问题,我的代码如下:
(老实说这个解法并不太好,只是为了完成任务,如果有更好的希望能告知我)
struct ListNode* addTwoNumbers(struct ListNode* l1, struct ListNode* l2) {
int n,coun =0;
struct ListNode *ptr ,*head ;
head =ptr= malloc(sizeof(struct ListNode));
for( ; ;)
{
if( l1 !=NULL)
{ n = l1->val;
l1 =l1->next;
}else
{
n =0;
}
if( l2 != NULL)
{
n += l2->val;
l2 = l2->next;
}
n += coun;
ptr->next = malloc(sizeof(struct ListNode));
ptr = ptr->next;
ptr->val = (n)%10;
coun =n/10;
if(l1==NULL &&l2==NULL&&coun==0)
{ptr->next =NULL;
break;
}
}
ptr=head->next;
free(head);
return(ptr);
}