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:
You may use one character in the keyboard more than once.You may assume the input string will only contain letters of alphabet.
题目大意：给定一组字符串，判断其中哪些可以由键盘上的某一行字母表示，输出满足条件的字符串所构成的字符串数组。
解题思路：定义一个长度为26的整型数组keyboard，keyboard[i]表示字符‘a’+1属于键盘上的第几行字母（第一行，第二行，或者第三行）。对每一个字符串进行判断，如果每一个字符都在同一行，则该字符串满足条件，否则不满足。
代码如下：（3ms，beats 82.87%）
public String[] findWords(String[] words) { int[] keyboard = new int[] { 2, 3, 3, 2, 1, 2, 2, 2, 1, 2, 2, 2, 3, 3, 1, 1, 1, 1, 2, 1, 1, 3, 1, 3, 1, 3 }; String[] temp = new String[words.length]; int index = 0; for (String word : words) { char[] chars = word.toLowerCase().toCharArray(); int len = chars.length; if (len == 0) break; int row = keyboard[chars[0] - 'a']; int i; for (i = 0; i < len; i++) { if (keyboard[chars[i] - 'a'] != row) break; } if (i == len) temp[index++] = word; } String[] res = new String[index]; for(int i=0;i<index;i++) res[i] = temp[i]; return res; }