500. Keyboard Row

public class Solution { public String[] findWords(String[] words) { String[] keys={"qwertyuiopQWERTYUIOP","asdfghjklASDFGHJKL","zxcvbnmZXCVBNM"}; List<String> list = new ArrayList<>(); for(int i = 0; i < words.length; i++) { if(isContains(keys,words[i])) { list.add(words[i]); } } String[] res = new String[list.size()]; for(int i = 0; i < list.size();i++) { res[i] = list.get(i); } return res; } public boolean isContains(String[] keys, String word) { int i = 0; for(i = 0; i < keys.length; i++) { if(keys[i].indexOf(word.charAt(0))>=0) { break; } } for(int j = 0; j < word.length(); j++) { if(keys[i].indexOf(word.charAt(j))<0) { return false; } } return true; } }