题目:
You are given two linked lists representing two non-negative numbers. The digits are
stored in reverse order and each of their nodes contains 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
解答:
1 public ListNode addTwoNumbers(ListNode l1, ListNode l2) { 2 ListNode dummyHead = new ListNode(0); 3 ListNode p = l1; 4 ListNode q = l2; 5 ListNode curr = dummyHead; 6 7 int carry = 0; 8 9 while(p != null || q != null) { 10 int x = (p != null)?p.val:0; 11 int y = (q != null)?q.val:0; 12 13 int digit = x + y + carry; 14 carry = digit / 10; 15 curr.next = new ListNode(digit % 10); 16 curr = curr.next; 17 18 if(p != null) { 19 p = p.next; 20 } 21 22 if(q != null) { 23 q = q.next; 24 } 25 } 26 27 if(carry > 0) { 28 curr.next = new ListNode(carry); 29 } 30 31 return dummyHead; 32 }