两个链表生成相加链表

import java.util.*;
import java.lang.*;


public class Solution {
      public static ListNode addInList (ListNode head1, ListNode head2) {
        Stack<ListNode> stack1 = new Stack<>();
        Stack<ListNode> stack2 = new Stack<>();
        while (head1 != null){
            stack1.push(head1);
            head1 = head1.next;
        }
        while (head2 != null){
            stack2.push(head2);
            head2 = head2.next;
        }
        int carryOver = 0;
        Stack<ListNode> minStack;
        Stack<ListNode> maxStack;
        maxStack = stack1.size() > stack2.size() ? stack1 : stack2;
        minStack = stack1.size() > stack2.size() ? stack2 : stack1;
        ListNode maxNode = null;
        while (!minStack.isEmpty() || !maxStack.isEmpty()){
            int minValue = 0;
            maxNode = maxStack.pop();
            if (!minStack.isEmpty()){
                minValue = minStack.pop().val;
            }
            int sum = maxNode.val + minValue + carryOver;
            carryOver = (sum - (sum % 10)) / 10;
            maxNode.val = sum % 10;
        }

        if (carryOver != 0){
            ListNode root = new ListNode(carryOver);
            root.next = maxNode;
            return root;
        }
        return maxNode;
    }

}