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.public class Solution { public String[] findWords(String[] words) { Set<Character> first=new HashSet<>(); Set<Character> secend=new HashSet<>(); Set<Character> third=new HashSet<>(); List<String> result = new ArrayList<>(); addword(first,secend,third); int[] count={0,0,0}; for(int i=0;i<words.length;i++) { char[] charArray = words[i].toLowerCase().toCharArray();//大写变小写和转变char数组 for(int j=0;j<words[i].length();j++)//当数据较大时，加快运行速度这里可以加几个if判断是否符合以便随时中断 { if(first.contains(charArray[j]))count[0]++; else if(secend.contains(charArray[j]))count[1]++; else if(third.contains(charArray[j]))count[2]++; } if(count[0]==words[i].length()||count[1]==words[i].length()||count[2]==words[i].length()) { result.add(words[i]); } for(int z=0;z<3;z++) { count[z]=0; } } return result.toArray(new String[result.size()]);//toArray()将list集合转变成数组形式 } public void addword(Set<Character> f,Set<Character> s,Set<Character> t){ String x="qwertyuiop",c="asdfghjkl",v="zxcvbnm"; for(Character i:x.toCharArray())//转变char数组 { f.add(i); } for(Character i:c.toCharArray()) { s.add(i); } for(Character i:v.toCharArray()) { t.add(i); } } } 接下来就是大神的代码： return Stream.of(words).filter(s -> s.toLowerCase().matches("[qwertyuiop]*|[asdfghjkl]*|[zxcvbnm]*")).toArray(String[]::new); }
