LeetCode2-Add (two numbers)

Question

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

Analysis:

This question is not difficult. It mainly involves detail analysis and control. A special case is that after the two columns are traversed, but the carry is 1, a new tail node is created to store this number.

Reference code:

/** * Definition for singly-linked list. * struct ListNode { *     int val; *     ListNode *next; *     ListNode(int x) : val(x), next(NULL) {} * }; */class Solution {public:    ListNode *addTwoNumbers(ListNode *l1, ListNode *l2) {        bool jw=0;        int num=0;        int sum=0;        int count = 0;        ListNode *result, *pre_node, *cur_node;        while (l1 != NULL && l2 != NULL)        {            sum = l1->val + l2->val + jw;            num = sum % 10;            cur_node = (ListNode *)malloc(sizeof(ListNode));            cur_node->val = num;            cur_node->next = NULL;            if (count == 0)            {                result = cur_node;                pre_node = cur_node;            }            else            {                pre_node->next = cur_node;                pre_node=pre_node->next;            }            l1 = l1->next;            l2 = l2->next;            count++;            jw=sum/10;        }        while (l1 != NULL)        {            sum = l1->val+jw;            num = sum % 10;            l1->val=num;            cur_node->next = l1;            cur_node=cur_node->next;            l1 = l1->next;            jw=sum/10;        }        while (l2 != NULL)        {            sum = l2->val+jw;            num = sum % 10;            l2->val=num;            cur_node->next = l2;            cur_node=cur_node->next;            l2 = l2->next;            jw=sum/10;        }        if(jw==1)        {            ListNode *tail=(ListNode *)malloc(sizeof(ListNode));            tail->val=jw;            cur_node->next=tail;            cur_node=cur_node->next;        }        cur_node->next = NULL;        return result;    }};

 

LeetCode2-Add (two numbers)