leetcode 第2题【两数相加】C语言

struct ListNode* addTwoNumbers(struct ListNode* l1, struct ListNode* l2) 
{
    int t=0; 
    struct ListNode* first=NULL;  
    struct ListNode* end=NULL;    
    while(l1||l2) 
    {
        int n1=  l1 ? l1->val : 0;  
        int n2=  l2 ? l2->val : 0;
        int sum=n1+n2+t;
        if(!first)
        {
            first=end=malloc(sizeof(struct ListNode)); 
            end->val=sum%10;   
            end->next=NULL;  
        }
        else
        {
            end->next=malloc(sizeof(struct ListNode));
            end->next->val=sum%10;
            end=end->next; 
        }
        t=sum/10; 
        if(l1)
        {
            l1=l1->next;
        }
        if(l2)
        {
            l2=l2->next;
        }
    }
    if(t) 
    {
    		 end->next=malloc(sizeof(struct ListNode));
    		 end->next->val=t; 
    		 end->next->next=NULL; 
    }
    return first; 
}

总结知识点：结构体定义、指针、三目运算符、循环体、链表