自己做的
/**
* Definition for singly-linked list.
* struct ListNode {
* int val;
* ListNode *next;
* ListNode() : val(0), next(nullptr) {}
* ListNode(int x) : val(x), next(nullptr) {}
* ListNode(int x, ListNode *next) : val(x), next(next) {}
* };
*/
class Solution {
public:
ListNode* addTwoNumbers(ListNode* l1, ListNode* l2) {
ListNode* start = l1;
int over = 0;
while(l1->next != nullptr && l2->next != nullptr){
int sum = over + l1->val + l2->val;
if(sum >= 10){
over = 1;
sum -= 10;
}
else{
over = 0;
}
l1->val = sum;
l1 = l1->next;
l2 = l2->next;
}
int sum = over + l1->val + l2->val;
if(sum >= 10){
over = 1;
sum -= 10;
}
else{
over = 0;
}
l1->val = sum;
if(!l1->next){
l1->next = l2->next;
}
while(over){
if(!l1->next){
l1->next = new ListNode(over, nullptr);
return start;
}
else{
sum = over + l1->next->val;
if(sum >= 10){
over = 1;
sum -= 10;
}
else{
over = 0;
}
l1->next->val = sum;
l1 = l1->next;
}
}
return start;
}
};
答案简洁一点
public ListNode addTwoNumbers(ListNode l1, ListNode l2) {
ListNode dummyHead = new ListNode(0);
ListNode p = l1, q = l2, curr = dummyHead;
int carry = 0;
while (p != null || q != null) {
int x = (p != null) ? p.val : 0;
int y = (q != null) ? q.val : 0;
int sum = carry + x + y;
carry = sum / 10;
curr.next = new ListNode(sum % 10);
curr = curr.next;
if (p != null) p = p.next;
if (q != null) q = q.next;
}
if (carry > 0) {
curr.next = new ListNode(carry);
}
return dummyHead.next;
}