leetcode-17. Letter Combinations of a Phone Number
来源:互联网 发布:开启手机休眠关闭网络 编辑:程序博客网 时间:2024/05/16 14:29
Given a digit string, return all possible letter combinations that the number could represent.
A mapping of digit to letters (just like on the telephone buttons) is given below.
Input:Digit string "23"Output: ["ad", "ae", "af", "bd", "be", "bf", "cd", "ce", "cf"].
Note:
Although the above answer is in lexicographical order, your answer could be in any order you want.
题意解析:
这道题和真实情景十分相似,回到那个诺基亚称霸的时代,这样的键盘可以说是标配,那个时候打字都用九宫格。那么我们按下两个数字以后,到底有哪几种组合呢,这道题就是要解决这样的问题。
解题思路:
思路其实很好想,首先必须要有个数据结构来保存数字和字母之间的对应关系,一看题目,key对应value,map当仁不让,不过这道题由于key是有序数字,所以创建一个String数组就可以了。然后就是对它们进行组合。根据输入的数字去map里找对应的内容,保存在结果集里返回。
具体做法是一个个读取数字,然后把对应的字母增加到结果集里,然后每读一个新数字,就遍历原来的结果集,给它加数字,代码如下:
public class Solution { public List<String> letterCombinations(String digits) { if(digits.length() == 0) return new LinkedList<String>(); String[] phoneNum = {"", "", "abc", "def", "ghi", "jkl", "mno", "pqrs", "tuv", "wxyz"}; List<String> result = new LinkedList<String>(); result.add(""); for(int i = 0; i < digits.length(); i++){ String a = phoneNum[digits.charAt(i) - '0']; List<String> temp = new LinkedList<String>(); for(int j = 0; j < a.length(); j++){ for(String x : result){ temp.add(x + a.charAt(j)); } } result = temp; } return result; }}
1 0
- LeetCode: Letter Combinations of a Phone Number
- LeetCode Letter Combinations of a Phone Number
- LeetCode: Letter Combinations of a Phone Number
- [Leetcode] Letter Combinations of a Phone Number
- [LeetCode] Letter Combinations of a Phone Number
- 【leetcode】Letter Combinations of a Phone Number
- LeetCode: Letter Combinations of a Phone Number
- [LeetCode]Letter Combinations of a Phone Number
- LeetCode-Letter Combinations of a Phone Number
- [LeetCode] Letter Combinations of a Phone Number
- LeetCode - Letter Combinations of a Phone Number
- LeetCode:Letter Combinations of a Phone Number
- LeetCode | Letter Combinations of a Phone Number
- leetcode Letter Combinations of a Phone Number
- Leetcode: Letter Combinations of a Phone Number
- 【leetcode】Letter Combinations of a Phone Number
- [LeetCode] Letter Combinations of a Phone Number
- leetcode: Letter Combinations of a Phone Number
- Android自由开发者 通过Jsoup抓取网页数据
- 关于autohotkey的一些文章
- mysql5.7版本安装出现的问题
- zabbix一键安装脚本
- CCF 有趣的数
- leetcode-17. Letter Combinations of a Phone Number
- 戏子SB啦啦
- YoMail 隐藏小功能之怎样在yomail里使用石墨文档?
- iOS如何在自己的手机上调试xcode程序
- 有50 只狗,找出其中病狗
- 在C#中用xslt文件格式化转换xml
- ajax返回值需要注意的地方
- SQL查询和判断语句
- Android HandlerThread 完全解析