[leetcode] 500. Keyboard Row

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.

这道题是判断单词能否由键盘某一行中字母组合而成，题目难度为Easy。

题目比较简单，将各行字母分别存入Hash Table中，然后逐个判断数组中字符串即可。具体代码：

class Solution {public:    vector<string> findWords(vector<string>& words) {        vector<string> ret;        unordered_map<char, int> hash;                hash['Q'] = hash['q'] = 1;        hash['W'] = hash['w'] = 1;        hash['E'] = hash['e'] = 1;        hash['R'] = hash['r'] = 1;        hash['T'] = hash['t'] = 1;        hash['Y'] = hash['y'] = 1;        hash['U'] = hash['u'] = 1;        hash['I'] = hash['i'] = 1;        hash['O'] = hash['o'] = 1;        hash['P'] = hash['p'] = 1;        hash['A'] = hash['a'] = 2;        hash['S'] = hash['s'] = 2;        hash['D'] = hash['d'] = 2;        hash['F'] = hash['f'] = 2;        hash['G'] = hash['g'] = 2;        hash['H'] = hash['h'] = 2;        hash['J'] = hash['j'] = 2;        hash['K'] = hash['k'] = 2;        hash['L'] = hash['l'] = 2;        hash['Z'] = hash['z'] = 3;        hash['X'] = hash['x'] = 3;        hash['C'] = hash['c'] = 3;        hash['V'] = hash['v'] = 3;        hash['B'] = hash['b'] = 3;        hash['N'] = hash['n'] = 3;        hash['M'] = hash['m'] = 3;                for(auto s:words) {            int row = hash[s[0]];            bool inOneRow = true;            for(auto c:s) {                if(hash[c] != row) {                    inOneRow = false;                    break;                }            }            if(inOneRow) ret.push_back(s);        }                return ret;    }};