2. Add Two Numbers, addtwonumbers

2. Add Two Numbers, addtwonumbers

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/** 2 * Definition for singly-linked list. 3 * struct ListNode {4 * int val; 5 * struct ListNode * next; 6 *}; 7 */8 struct ListNode * addTwoNumbers (struct ListNode * l1, struct ListNode * l2) {9 struct ListNode * phead; 10 struct ListNode * cur1; 11 struct ListNode * cur2; 12 struct ListNode * curp; 13 struct ListNode * dele; 14 struct ListNode * pnew; 15 phead = NULL; 16 cur1 = l1; 17 cur2 = l2; 18 int flag = 0; 19 while (cur1! = NULL | cur2! = NULL) 20 {21 if (phead = NULL) 22 {23 curp = (struct ListNode *) malloc (sizeof (struct ListNode); 24 memset (curp, 0, sizeof (struct ListNode); 25 phead = curp; 26} 27 else28 {29 pnew = (struct ListNode *) malloc (sizeof (struct ListNode); 30 memset (pnew, 0, sizeof (struct ListNode); 31 curp-> next = pnew; 32 curp = pnew; 33} 34 if (cur1 = NULL) 35 {36 curp-> val = (cur2-> val + flag) % 10; 37 flag = (cur2-> val + flag )/10; 38 dele = cur2; 39 cur2 = cur2-> next; 40 free (dele); 41 dele = NULL; 42} 43 else if (cur2 = NULL) 44 {45 curp-> val = (cur1-> val + flag) % 10; 46 flag = (cur1-> val + flag)/10; 47 dele = cur1; 48 cur1 = cur1-> next; 49 free (dele); 50 dele = NULL; 51} 52 else53 {54 curp-> val = (cur1-> val + flag + cur2-> val) % 10; 55 flag = (cur1-> val + flag + cur2-> val)/10; 56 dele = cur2; 57 cur2 = cur2-> next; 58 free (del E); 59 dele = NULL; 60 dele = cur1; 61 cur1 = cur1-> next; 62 free (dele); 63 dele = NULL; 64} 65 66} 67 if (flag = 1) // pay attention to the carry problem at last !!! 68 {69 pnew = (struct ListNode *) malloc (sizeof (struct ListNode); 70 memset (pnew, 0, sizeof (struct ListNode )); 71 curp-> next = pnew; 72 pnew-> val = 1; 73 return phead; 74} 75 return phead; 76}