题解 | #两个链表生成相加链表#
两个链表生成相加链表
http://www.nowcoder.com/practice/c56f6c70fb3f4849bc56e33ff2a50b6b
import java.util.*;
/*
* public class ListNode {
* int val;
* ListNode next = null;
* }
*/
public class Solution {
/**
*
* @param head1 ListNode类
* @param head2 ListNode类
* @return ListNode类
*/
public ListNode addInList (ListNode head1, ListNode head2) {
ListNode head1Reverse = reverse(head1);
ListNode head2Reverse = reverse(head2);
ListNode newHead = new ListNode(-1);
ListNode curNode = newHead;
int preAdd = 0;
while(head1Reverse != null || head2Reverse!=null){
int v1 = head1Reverse == null? 0: head1Reverse.val;
int v2 = head2Reverse == null? 0: head2Reverse.val;
int curVal = (v1+v2 + preAdd) % 10;
preAdd = (v1+v2 + preAdd) / 10;
ListNode node = new ListNode(curVal);
curNode.next = node;
curNode = node;
head1Reverse = head1Reverse == null? null: head1Reverse.next;
head2Reverse = head2Reverse == null? null: head2Reverse.next;
}
if(preAdd == 1){
ListNode node = new ListNode(1);
curNode.next = node;
}
return reverse(newHead.next);
}
public static ListNode reverse(ListNode head){
ListNode pre = null;
ListNode cur = head;
while(cur != null){
ListNode next = cur.next;
cur.next = pre;
pre = cur;
cur = next;
}
return pre;
}
}