【LeetCode】500. Keyboard Row

来源：互联网发布：2017学校网络改造方案编辑：程序博客网时间：2024/06/06 02:32

问题描述

问题链接：https://leetcode.com/problems/keyboard-row/#/description

Given a List of words, return the words that can be typed using letters of alphabet on only one row’s of American keyboard like the image below.

Example 1:

Input: ["Hello", "Alaska", "Dad", "Peace"]Output: ["Alaska", "Dad"]

Note:

You may use one character in the keyboard more than once.

You may assume the input string will only contain letters of alphabet.

我的代码

这题的思路非常简单，我就直接贴代码了。遇到的坑主要是API不记得了。以后会把学过的Trick整理出来，方便今后复习。

public class Solution {    private static String rowOne = "qwertyuiopQWERTYUIOP";    private static String rowTwo = "asdfghjklASDFGHJKL";    private static String rowThree = "zxcvbnmZXCVBNM";    public String[] findWords(String[] words) {        /*        思路是首先创建3个列表，分别包含键盘中3行的字母的大小写，        然后遍历输入的单词，判断每个单词的所有字母是不是都出现在同一个列表中，        如果是，那么这个单词符合要求，否则不符合要求        */        List<String> wordList = new ArrayList<String>();        for(String word : words){           if(canInput(word)){               wordList.add(word);           }        }        String[] results = new String[wordList.size()];        return wordList.toArray(results);    }    private boolean canInput(String word){        char c = word.charAt(0);        String checkRow = rowThree;        if(rowOne.indexOf(c) >= 0){            checkRow = rowOne;        }else if(rowTwo.indexOf(c) >= 0){            checkRow = rowTwo;        }        for(int i = 1; i < word.length(); i++){            char ch = word.charAt(i);            if(checkRow.indexOf(ch) < 0){                return false;            }        }        return true;    }}

这次我打败了98.38%的Java代码！哈哈哈好开心。

讨论区

来，再到讨论区看看大神们的代码。

Short Easy Java with Explanation

链接地址：https://discuss.leetcode.com/topic/77773/short-easy-java-with-explanation

 public string[] FindWords(string[] words)     {        int[] row1 = ToCountArr("qwertyuiop");        int[] row2 = ToCountArr("asdfghjkl");        int[] row3 = ToCountArr("zxcvbnm");        return words.Where(w => All(row1, w) || All(row2, w) || All(row3, w)).ToArray();    }    public int[] ToCountArr(string s)    {        int[] arr = new int[26];        foreach (char c in s)        {            arr[c - 'a'] = 1;        }        return arr;    }    public bool All(int[] row, string input)    {        foreach (char c in input.ToLower())        {            if (row[c-'a'] == 0) return false;        }        return true;    }

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