https://leetcode.com/problems/keyboard-row/
首先我们把键盘的三行字符分别保存到三个set中，然后遍历每个单词中的每个字符，分别看当前字符是否在三个集合中，如果在，对应的标识变量变为1，我们统计三个标识变量之和就知道有几个集合参与其中了
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.
首先我们把键盘的三行字符分别保存到三个set中，然后遍历每个单词中的每个字符，分别看当前字符是否在三个集合中，如果在，对应的标识变量变为1，我们统计三个标识变量之和就知道有几个集合参与其中了
vector<string> findWords(vector<string>& words) { vector<string> res; unordered_set<char> row1{'q','w','e','r','t','y','u','i','o','p'}; unordered_set<char> row2{'a','s','d','f','g','h','j','k','l'}; unordered_set<char> row3{'z','x','c','v','b','n','m'}; for (string word : words) { int one = 0, two = 0, three = 0; for (char c : word) { if (c < 'a') c += 32; if (row1.count(c)) one = 1; if (row2.count(c)) two = 1; if (row3.count(c)) three = 1; if (one + two + three > 1) break; } if (one + two + three == 1) res.push_back(word); } return res; }判断输入单词的字母集合是否为键盘某一行字母集合的子集
public String[] findWords(String[] words) {
String[] strs = {"QWERTYUIOP","ASDFGHJKL","ZXCVBNM"};
Map<Character, Integer> map = new HashMap<>();
for(int i = 0; i<strs.length; i++){
for(char c: strs[i].toCharArray()){
map.put(c, i);//put <char, rowIndex> pair into the map
}
}
List<String> res = new LinkedList<>();
for(String w: words){
if(w.equals("")) continue;
int index = map.get(w.toUpperCase().charAt(0));
for(char c: w.toUpperCase().toCharArray()){
if(map.get(c)!=index){
index = -1; //don't need a boolean flag.
break;
}
}
if(index!=-1) res.add(w);//if index != -1, this is a valid string
}
return res.toArray(new String[0]);
}
def findWords(self, words):
"""
:type words: List[str]
:rtype: List[str]
"""
rs = map(set, ['qwertyuiop','asdfghjkl','zxcvbnm'])
ans = []
for word in words:
wset = set(word.lower())
if any(wset <= rset for rset in rs):
ans.append(word)
return ans
public String[] findWords(String[] words) {
return Stream.of(words).filter(s -> s.toLowerCase().matches("[qwertyuiop]*|[asdfghjkl]*|[zxcvbnm]*")).toArray(String[]::new);
}