給定一個單詞列表，只返回可以使用在鍵盤同一行的字母列印出來的單詞。鍵盤如下圖所示。

示例：

輸入: [“Hello”, “Alaska”, “Dad”, “Peace”]
輸出: [“Alaska”, “Dad”]

注意：

你可以重複使用鍵盤上同一字元。
你可以假設輸入的字串將只包含字母。

Python

class Solution(object):
    def findWords(self, words):
        set1 = set("qwertyuiop")
        set2 = set("asdfghjkl")
        set3 = set("zxcvbnm")
        res = []
        for i in words:
            x = i.lower()##lower函式,整個字串直接變小寫
            setx = set(x)
            if setx <= set1 or setx <= set2 or setx <= set3:##如果set是set1,set2或set3的子集,則壓入res中
                res.append(i)
        return res

C++

class Solution {
public:
    vector<string> findWords(vector<string>& words) {
        vector<string> res;
        string s1 = "qwertyuiop";
        string s2 = "asdfghjkl";
        string s3 = "zxcvbnm";
        for(int i = 0; i < words.size(); i++){
            int a = 0, b = 0, c = 0;
            for(auto x : words[i]){
                if(s1.find(tolower(x)) != string::npos) a++;
                if(s2.find(tolower(x)) != string::npos) b++;
                if(s3.find(tolower(x)) != string::npos) c++;
            }
            if(words[i].size() == a || words[i].size() == b || c == words[i].size())
                res.push_back(words[i]);
        }
        return res;
    }
};