题解 | #牛群的能量值#

/**
 * struct ListNode {
 *	int val;
 *	struct ListNode *next;
 *	ListNode(int x) : val(x), next(nullptr) {}
 * };
 */
class Solution {
public:
    /**
     * 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 l1 ListNode类 
     * @param l2 ListNode类 
     * @return ListNode类
     */
    ListNode* addEnergyValues(ListNode* l1, ListNode* l2) {
        // write code here
        int flag = 0;
        ListNode* a = l1;
        ListNode* b = l2;
        ListNode* res  = l1;
        int alen = 0;
        int blen = 0;
        while(a != nullptr)
        {
            alen++;
            a =a->next;
        }
        while(b != nullptr)
        {
            blen++;
            b = b->next;
        }

        a = l1;
        b = l2;
        if(alen < blen)
        {
            swap(a, b);
            res = l2;
        } 

        while (a->next != nullptr) {
            if(b != nullptr)
            {
                a->val = a->val + b->val + flag;
                if(a->val >= 10)
                {
                    a->val = a->val % 10;
                    flag = 1;
                    a = a->next;
                    b = b->next;
                    continue;
                }
                a = a->next;
                b = b->next;
                flag = 0;
            }else {
                a->val = a->val + flag;
                if(a->val >= 10)
                {
                    a->val = a->val % 10;
                    flag = 1;
                    a = a->next;
                    continue;
                }
                a = a->next;
                flag = 0; 
            }
     
         
        }

        if(b) a->val  =  a->val + b->val + flag;
        else a->val += flag;
        if(a->val >= 10)
        {
            a->val = a->val % 10;
            a->next = new ListNode(1);
        }
          

        return res;
    }
};