500. Keyboard Row(for...)

感觉还蛮尴尬的，学 cpp 也有一段时间了，居然不知道 for 还有这样的使用。
不说了，贴题目和代码。

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.


American keyboard


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.

class Solution {
public:
    vector<string> findWords(vector<string>& words) {
        vector<string> outStr;
        string qwe = "qwertyuiopQWERTYUIOP";
        string asd = "asdfghjklASDFGHJKL";
        string zxc = "zxcvbnmZXCVBNM";

        for (auto &word:words)
        {
          bool f1 = true;
          bool f2 = true;
          bool f3 = true;
          for (auto &ch:word)
          {
              for (int i = 0; i < qwe.length(); i++)
              {
                  if (ch == qwe[i])
                  {
                     f1 = false;
                     break;
                  }
              }
              for (int i = 0; i < asd.length(); i++)
              {
                  if (ch == asd[i])
                  {
                     f2 = false;
                     break;
                  }
              }
              for (int i = 0; i < zxc.length(); i++)
              {
                  if (ch == zxc[i])
                  {
                     f3 = false;
                     break;
                  }
              }
          }
            if(f1 == true && f2 == true && f3 == false) outStr.push_back(word);
            if(f1 == false && f2 == true && f3 == true) outStr.push_back(word);
            if(f1 == true && f2 == false && f3 == true) outStr.push_back(word);
        }
        return outStr;
    }
};

写 cpp 到现在，还比较抵触容器，还是比较习惯 c 里面的数组的概念，但数组也很不好用。
今天才知道 for (auto &word:words) 还可以这样使用 for 的，那不是美滋滋吗。

记住！