题解 | #链表相加(二)#
链表相加(二)
https://www.nowcoder.com/practice/c56f6c70fb3f4849bc56e33ff2a50b6b
/**
* @author Lu.F
* @version 1.0
* @date 2022/10/8 22:06
*/
public class Solution301 {
/**
* 运用栈 先进后出特点
* @param head1 ListNode类
* @param head2 ListNode类
* @return ListNode类
*/
public ListNode addInList (ListNode head1, ListNode head2) {
// write code here
if (head1 == null){
return head2;
}
if (head2 == null){
return head1;
}
// 栈
Stack<Integer> stack1 = new Stack<>();
Stack<Integer> stack2 = new Stack<>();
while (head1 != null){
stack1.push(head1.val);
head1 = head1.next;
}
while (head2 != null){
stack2.push(head2.val);
head2 = head2.next;
}
// 进位
int temp = 0;
ListNode pHead = new ListNode(-1);
ListNode head = pHead.next;
while (!stack1.isEmpty() || !stack2.isEmpty()){
int val = temp;
if (!stack1.isEmpty()){
val += stack1.pop();
}
if (!stack2.isEmpty()){
val += stack2.pop();
}
// 头插法
temp = val/10;
ListNode node = new ListNode(val%10);
node.next = head;
head = node;
}
// 头插法
if (temp > 0){
ListNode node = new ListNode(temp);
node.next = head;
head = node;
}
return head;
}
}
