标签：stream character 参考 back letter 代码 png 参考资料 ref
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:
这道题给了我们一些单词，问哪些单词可以由键盘上的一行中的键符打出来，难度其实并不大。首先我们把键盘的三行字符分别保存到三个set中，然后遍历每个单词中的每个字符，分别看当前字符是否在三个集合中，如果在，对应的标识变量变为1，我们统计三个标识变量之和就知道有几个集合参与其中了，参见代码如下：
class Solution { public: vector<string> findWords(vector<string>& words) { vector<string> res; unordered_set<char> row1{‘q‘,‘w‘,‘e‘,‘r‘,‘t‘,‘y‘,‘u‘,‘i‘,‘o‘,‘p‘}; unordered_set<char> row2{‘a‘,‘s‘,‘d‘,‘f‘,‘g‘,‘h‘,‘j‘,‘k‘,‘l‘}; unordered_set<char> row3{‘z‘,‘x‘,‘c‘,‘v‘,‘b‘,‘n‘,‘m‘}; for (string word : words) { int one = 0, two = 0, three = 0; for (char c : word) { if (c < ‘a‘) c += 32; if (row1.count(c)) one = 1; if (row2.count(c)) two = 1; if (row3.count(c)) three = 1; if (one + two + three > 1) break; } if (one + two + three == 1) res.push_back(word); } return res; } };
参考资料：
https://discuss.leetcode.com/topic/77754/java-1-line-solution-via-regex-and-stream
LeetCode All in One 题目讲解汇总(持续更新中...)
标签：stream character 参考 back letter 代码 png 参考资料 ref
原文地址：http://www.cnblogs.com/grandyang/p/6421749.html
