Medium
L面经题，几百年没刷LinkedList的题了，这道题处理小细节也提交了好几次，其实是道很简单的题
/**
* Definition for singly-linked list.
* public class ListNode {
* int val;
* ListNode next;
* ListNode(int x) { val = x; }
* }
*/
class Solution {
public ListNode addTwoNumbers(ListNode l1, ListNode l2) {
ListNode dummy = new ListNode(0);
ListNode curt = dummy;
int carry = 0;
ListNode curt1 = l1;
ListNode curt2 = l2;
int sum = 0;
while (curt1 != null && curt2 != null){
sum = curt1.val + curt2.val + carry;
carry = 0;
if (sum >= 10){
carry++;
sum %= 10;
}
curt.next = new ListNode(sum);
curt = curt.next;
curt1 = curt1.next;
curt2 = curt2.next;
sum = 0;
}
while (curt1 != null){
sum = curt1.val + carry;
carry = 0;
if (sum >= 10){
carry++;
sum %= 10;
}
curt.next = new ListNode(sum);
curt = curt.next;
curt1 = curt1.next;
sum = 0;
}
while (curt2 != null){
sum = curt2.val + carry;
carry = 0;
if (sum >= 10){
carry++;
sum %= 10;
}
curt.next = new ListNode(sum);
curt = curt.next;
curt2 = curt2.next;
sum = 0;
}
if (carry != 0){
curt.next = new ListNode(carry);
}
return dummy.next;
}
}
