Question Definition
You are given two non-empty linked lists representing two non-negative integers. 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.
You may assume the two numbers do not contain any leading zero, except the number 0 itself.
Example
Input: (2 -> 4 -> 3) + (5 -> 6 -> 4)
Output: 7 -> 0 -> 8
Explanation: 342 + 465 = 807.
Java Solution
public ListNode addTwoNumbers(ListNode l1, ListNode l2) {
if(l1 == null) return l2;
if(l2 == null) return l1;
ListNode head = null;
ListNode tail = null;
boolean acc = false;
while(l1 != null && l2 != null){
System.out.println(l1.val + ":" + l2.val);
int val = l1.val + l2.val;
if(acc)
val++;
if(val > 9){
acc = true;
val = val % 10;
}else
acc = false;
ListNode temp = new ListNode(val);
if(head == null){
head = temp;
tail = temp;
}
else{
tail.next = temp;
tail = temp;
}
l1 = l1.next;
l2 = l2.next;
}
while(l1 != null){
int val = l1.val;
if(acc)
val++;
if(val > 9){
acc = true;
val = val % 10;
}else
acc = false;
ListNode temp = new ListNode(val);
if(head == null){
head = temp;
tail = temp;
}
else{
tail.next = temp;
tail = temp;
}
l1 = l1.next;
}
while(l2 != null){
int val = l2.val;
if(acc)
val++;
if(val > 9){
acc = true;
val = val % 10;
}else
acc = false;
ListNode temp = new ListNode(val);
if(head == null){
head = temp;
tail = temp;
}
else{
tail.next = temp;
tail = temp;
}
l2 = l2.next;
}
if(acc){
ListNode temp = new ListNode(1);
tail.next = temp;
}
return head;
}
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