Description

You have two numbers represented by a linked list, where each node contains a single digit. The digits are stored in reverse order, such that the 1's digit is at the head of the list. Write a function that adds the two numbers and returns the sum as a linked list.

Example

Given 7->1->6 + 5->9->2. That is, 617 + 295.

Return 2->1->9. That is 912.

Given 3->1->5 and 5->9->2, return 8->0->8

解题:题目的意思是,给两个链表,倒序表示一个若干位的数。要求返回这两个数的和,并且格式是题中规定的链表,也是倒序。思路很清晰,从头到尾,一位一位地相加,并且用一个数来保存进位。每次相加的时候,都得考虑进位,把进位算在其中。当然,思路越清晰,代码可能看起来就比较笨重。代码如下:

 /**
* Definition for ListNode
* public class ListNode {
* int val;
* ListNode next;
* ListNode(int x) {
* val = x;
* next = null;
* }
* }
*/ public class Solution {
/**
* @param l1: the first list
* @param l2: the second list
* @return: the sum list of l1 and l2
*/
public ListNode addLists(ListNode l1, ListNode l2) {
// write your code here
ListNode head = new ListNode(0);
ListNode p=head;
ListNode p1 = l1;
ListNode p2 = l2;
int sum = 0;//保存每一位的和
int more=0;//保存进位
while(p1 != null && p2 != null){
sum = p1.val + p2.val+more;
more = sum / 10;
sum = sum % 10;
ListNode temp = new ListNode(sum);
p.next = temp;
p=p.next;
p1 = p1.next;
p2 = p2.next;
}
//如果more不为0
sum = 0;
while(p1 != null){
sum = more + p1.val;
more = sum / 10;
sum = sum % 10;
ListNode temp = new ListNode(sum);
p.next = temp;
p = p.next;
p1 = p1.next;
}
while(p2 != null){
sum = more + p2.val;
more = sum / 10;
sum = sum % 10;
ListNode temp = new ListNode(sum);
p.next = temp;
p = p.next;
p2 = p2.next;
}
if(more != 0){ //如果more不为0,那么最高位就是前面的进位
ListNode temp = new ListNode(more);
p.next = temp;
}
return head.next;
}
}

代码可能有点冗余,曾尝试改进,但发现还是这样写看起来比较清晰。如有错误,欢迎批评指正。

167. Add Two Numbers【LintCode by java】的更多相关文章

  1. 156. Merge Intervals【LintCode by java】

    Description Given a collection of intervals, merge all overlapping intervals. Example Given interval ...

  2. 167. Add Two Numbers【easy】

    You have two numbers represented by a linked list, where each node contains a single digit. The digi ...

  3. 212. Space Replacement【LintCode by java】

    Description Write a method to replace all spaces in a string with %20. The string is given in a char ...

  4. 30. Insert Interval【LintCode by java】

    Description Given a non-overlapping interval list which is sorted by start point. Insert a new inter ...

  5. * 197. Permutation Index【LintCode by java】

    Description Given a permutation which contains no repeated number, find its index in all the permuta ...

  6. 165. Merge Two Sorted Lists【LintCode by java】

    Description Merge two sorted (ascending) linked lists and return it as a new sorted list. The new so ...

  7. 158. Valid Anagram【LintCode by java】

    Description Write a method anagram(s,t) to decide if two strings are anagrams or not. Clarification ...

  8. 177. Convert Sorted Array to Binary Search Tree With Minimal Height【LintCode by java】

    Description Given a sorted (increasing order) array, Convert it to create a binary tree with minimal ...

  9. 173. Insertion Sort List【LintCode by java】

    Description Sort a linked list using insertion sort. Example Given 1->3->2->0->null, ret ...

随机推荐

  1. HUD 1288 Hat's Tea(反向的贪心,非常好的一道题)

    传送门:http://acm.hdu.edu.cn/showproblem.php?pid=1288 Hat's Tea Time Limit: 2000/1000 MS (Java/Others)  ...

  2. Kubernetes组件与架构

    转载请标明出处: 文章首发于>https://www.fangzhipeng.com/kubernetes/2018/09/30/k8s-basic1/ 本文出自方志朋的博客 Kubernete ...

  3. 『ACM C++』 PTA 天梯赛练习集L1 | 048-49

    今日刷题048-049 ------------------------------------------------L1-048---------------------------------- ...

  4. 【LightOJ 1081】Square Queries(二维RMQ降维)

    Little Tommy is playing a game. The game is played on a 2D N x N grid. There is an integer in each c ...

  5. 在JSP中使用formatNumber控制要显示的小数位数

    先引入标签库 <%@ taglib uri="http://java.sun.com/jsp/jstl/fmt" prefix="fmt" %> 比 ...

  6. cut 的用法

    cut 文件内容查看 显示行中的指定部分,删除文件中指定字段 显示文件的内容,类似于下的type命令. 说明 该命令有两项功能,其一是用来显示文件的内容,它依次读取由参数file所指明的文件,将它们的 ...

  7. 分享一个hybrid框架ionic

    ionic 是一个 HTML5 应用程序开发框架. 可以使用 HTML.CSS 和 Javascript 构建接近原生体验的移动应用程序.具有速度快,界面现代化.美观等特点.下面一起看一下如何使用 安 ...

  8. sourcetree .git 强制忽略指定文件不提交

    在公司写项目,大部分都会用到 svn 或 git 提交代码到服务器.我们公司用的GIT,每个程序员有自己的独立分支,各写各的代码互不冲突,最终合并到主分支再解决相同代码冲突问题.这时候会遇到一些配置文 ...

  9. Currency Helper

    using System; using Microsoft.Xrm.Sdk; using Microsoft.Crm.Sdk.Messages; /// <summary> /// 货币 ...

  10. 大数据学习--day09(this、static)

    this.static this 关键字 类不可以定义 this 属性 ,  但是每个类都有一个 隐藏起来的 this 属性  . 每个对象被创建了 , 都会给其属性分配空间  , 也会给 this  ...