题目描述：

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:

1. You may use one character in the keyboard more than once.
2. You may assume the input string will only contain letters of alphabet.

解题思路：

判断输入的每个单词中的字母是否都在键盘的同一行上。

代码：

1 class Solution { 2 public: 3     vector
     
       findWords(vector
      
       & words) { 4         vector
       
         ret; 5         for (auto word : words) { 6             bool sig = true; 7             char c = tolower(word[0]); 8             int num = alpha[c]; 9             for (int i = 1; i < word.size(); ++i) {10                 c = tolower(word[i]);11                 if (alpha[c] != num) {12                     sig = false;13                     break;14                 }15             }16             if (sig)17                 ret.push_back(word);18         }19         return ret;20     }21     22     unordered_map
        
          alpha = {23         {
   'q', 1}, {
   'w', 1}, {
   'e', 1}, {
   'r', 1}, {
   't', 1}, {
   'y', 1}, {
   'u', 1}, {
   'i', 1}, {
   'o', 1}, {
   'p', 1},24         {
   'a', 2}, {
   's', 2}, {
   'd', 2}, {
   'f', 2}, {
   'g', 2}, {
   'h', 2}, {
   'j', 2}, {
   'k', 2}, {
   'l', 2},25         {
   'z', 3}, {
   'x', 3}, {
   'c', 3}, {
   'v', 3}, {
   'b', 3}, {
   'n', 3}, {
   'm' ,3}26     };27 };