LeetCode [2] AddTwoNumbers

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

 

public class AddTwoNumbers {
	public static void main(String[] args){
		ListNode l1= new ListNode(1);
		l1.next = new ListNode(8);
		ListNode l2= new ListNode(0);
		addTwoNumbers(l1, l2);
	}
	
	
	public static ListNode addTwoNumbers(ListNode l1, ListNode l2) {
		ListNode result = new ListNode(0);
		ListNode frontNode = result;
		double result1 = createData(l1);
		double result2 = createData(l2);
		
		long result3 = (long)(result1 + result2);
		String resultString = String.valueOf(result3);
		char[] a = resultString.toCharArray();
		result.val = a[a.length-1]-'0';
		
		for(int i = a.length-2; i>=0; i--){
			ListNode l = new ListNode(a[i]-'0');
			frontNode.next = l;
			frontNode = l;
		}
		return result;
    }
	
	private static double createData(ListNode node){
		double result = 0;
		ListNode tempNode = node;
		int i =1;
		result = result + tempNode.val;
		while(tempNode.next != null){
			tempNode = tempNode.next;
			result = result + Math.pow(10,i)* tempNode.val;
			i++;
		}
		
		return result;
	}
	
	
}

class ListNode {
    int val;
      ListNode next;
      ListNode(int x) { val = x; }
}