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
solution:
/**
* Definition for singly-linked list.
* public class ListNode {
* int val;
* ListNode next;
* ListNode(int x) {
* val = x;
* next = null;
* }
* }
*/
public class Solution {
public ListNode addTwoNumbers(ListNode l1, ListNode l2) {
String result = ""; //保存最后的结果
int temp = 0; //保存进位
int value = 0; //保存结果的每一位的值
ListNode resultNode = new ListNode(0);
ListNode p = l1;
ListNode q = l2;
while(p != null && q != null){
int a = p.val;
int b = q.val;
int sum = a+b;
sum = sum + temp;
if(sum >= 10){
temp = 1;
}else{
temp = 0;
}
value = sum % 10;
result = result+value;
p = p.next;
q = q.next;
}
while(p != null){
int a = p.val;
int sum = a+temp;
if(sum>=10){
temp = 1;
}else{
temp = 0;
}
value = sum % 10;
result = result+value;
p = p.next;
}
while(q != null){
int b = q.val;
int sum = b+temp;
if(sum>=10){
temp = 1;
}else{
temp = 0;
}
value = sum % 10;
result = result+value;
q = q.next;
}
if(temp == 1){
result = result + temp;
}
if(result == "0"){
return new ListNode(0);
}
int k = 0;
while(k<result.length()){
int res = Integer.parseInt( String.valueOf(result.charAt(k)),10);
ListNode node = new ListNode(res);
ListNode resultP = resultNode;
while(resultP.next!=null) resultP = resultP.next;
resultP.next = node;
node.next = null;
k += 1;
}
ListNode newResultNode = resultNode.next;
return newResultNode;
}
}