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
1 class Solution { 2 public: 3 ListNode *addTwoNumbers(ListNode *l1, ListNode *l2) { 4 if(!l1&&!l2) return NULL; 5 if(!l1||!l2) return l1?l1:l2; 6 7 int overdigit = 0; 8 ListNode *p1 = l1; 9 ListNode *p2 = l2;10 ListNode *phead = NULL;11 ListNode *pbody = NULL;12 13 while(p1&&p2){14 int each_digit_val = p1->val + p2->val + overdigit;15 16 ListNode *pnew = new ListNode(each_digit_val%10);17 if(!phead) phead = pnew;18 19 if(!pbody) pbody = pnew;20 else{21 pbody->next = pnew;22 pbody = pnew;23 }24 25 if(each_digit_val>=10) overdigit = 1;26 else overdigit = 0;27 28 p1 = p1->next;p2 = p2->next;29 }30 31 ListNode *p3 = p1?p1:p2;32 while(p3||overdigit==1){33 ListNode *pnew = new ListNode(p3?((p3->val + overdigit)%10):overdigit);34 pbody->next = pnew;35 pbody = pnew;36 37 if(((p3?(p3->val):0) + overdigit)>=10) overdigit = 1;38 else overdigit = 0;39 p3 = p3?p3->next:NULL;40 }41 return phead;42 }43 };
[Leetcode] add two numbers