// Keyboard Row class Solution { public: vector findWords(vector& words) { vector r; string a = "qwertyuiop", b = "asdfghjkl", c = "zxcvbnm"; int d[127]; for (auto i: a) d[i] = d[i-32] = 0; for (auto i: b) d[i] = d[i-32] = 1; for (auto i: c) d[i] = d[i-32] = 2; for (auto word: words) { int e[3] = {}; for (auto c: word) e[d[c]]++; if (*max_element(e, e+3) == word.size()) r.push_back(word); } return r; } };