题解 | 链表相加(二)

/**
 * 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 head1 ListNode类
     * @param head2 ListNode类
     * @return ListNode类
     */
    ListNode* addInList(ListNode* pHead1, ListNode* pHead2) {
        ListNode* reverseList_1, * reverseList_2;
        ListNode* nList = NULL;
        ListNode* t1 = pHead1;
        ListNode* t2 = pHead2;
        reverseList_1 = (ListNode*)malloc(sizeof(ListNode));
        reverseList_2 = (ListNode*)malloc(sizeof(ListNode));
        if (pHead1 == NULL && pHead2 != NULL) {
            return pHead2;
        }
        if (pHead1 != NULL && pHead2 == NULL) {
            return pHead2;
        }
        if (pHead1 == NULL && pHead2 == NULL) {
            return NULL;
        }
        int count = 0;
        while (t1 != NULL) {
            if (count == 0) {
                ListNode* temp = (ListNode*)malloc(sizeof(ListNode));
                temp->val = t1->val;
                temp->next = NULL;
                reverseList_1 = temp;
            } else {
                ListNode* temp = (ListNode*)malloc(sizeof(ListNode));
                temp->val = t1->val;
                temp->next = reverseList_1;
                reverseList_1 = temp;
            }
            count++;
            t1 = t1->next;
        }
        count = 0;
        while (t2 != NULL) {
            if (count == 0) {
                ListNode* temp = (ListNode*)malloc(sizeof(ListNode));
                temp->val = t2->val;
                temp->next = NULL;
                reverseList_2 = temp;
            } else {
                ListNode* temp = (ListNode*)malloc(sizeof(ListNode));
                temp->val = t2->val;
                temp->next = reverseList_2;
                reverseList_2 = temp;
            }
            count++;
            t2 = t2->next;
        }
        count = 0;
        int addFlag = 0;//进位标志位
        while (reverseList_1 != NULL && reverseList_2 != NULL) {
            ListNode* rev1 = reverseList_1;
            ListNode* rev2 = reverseList_2;
            if (count == 0) {
                int sums = rev1->val + rev2->val;
                ListNode* temp = (ListNode*)malloc(sizeof(ListNode));
                nList = temp;
                temp->val = sums % 10;
                temp->next = NULL;
                addFlag += (sums - temp->val);
                reverseList_1 = reverseList_1->next;
                free(rev1);
                reverseList_2 = reverseList_2->next;
                free(rev2);
            } else {
                int sums = rev1->val + rev2->val + addFlag / 10;
                ListNode* temp = (ListNode*)malloc(sizeof(ListNode));
                temp->next = nList;;
                nList = temp;
                temp->val = sums % 10;
                addFlag = (sums - temp->val);
                reverseList_1 = reverseList_1->next;
                free(rev1);
                reverseList_2 = reverseList_2->next;
                free(rev2);
            }
            count++;
        }
        if (reverseList_1 != NULL) {
            while (reverseList_1 != NULL) {
                ListNode* rev1 = reverseList_1;
                int sums = reverseList_1->val + addFlag / 10;
                ListNode* temp = (ListNode*)malloc(sizeof(ListNode));
                temp->val = sums % 10;
                addFlag = (sums - temp->val);
                temp->next = nList;
                nList = temp;
                reverseList_1 = reverseList_1->next;
                free(rev1);
            }
        }
        if (reverseList_2 != NULL) {
            while (reverseList_2 != NULL) {
                ListNode* rev1 = reverseList_2;
                int sums = reverseList_2->val + addFlag / 10;
                ListNode* temp = (ListNode*)malloc(sizeof(ListNode));
                temp->val = sums % 10;
                temp->next=nList;
                nList=temp;
                addFlag = (sums - temp->val);
                reverseList_2 = reverseList_2->next;
                free(rev1);
            }
        }
        if (addFlag == 10) {
            ListNode* temp = (ListNode*)malloc(sizeof(ListNode));
            temp->val = 1;
            temp->next = nList;
            nList = temp;
        }
        return nList;
    }
};

结题思路改天再写，要睡觉了