Keyboard Row

 1 public class Solution {
 2     public String[] findWords(String[] words) {
 3         List<String> result = new ArrayList<String>();
 4         Character[] row1 = {‘Q‘, ‘W‘, ‘E‘, ‘R‘, ‘T‘, ‘Y‘, ‘U‘, ‘I‘, ‘O‘, ‘P‘};
 5         Character[] row2 = {‘A‘, ‘S‘, ‘D‘, ‘F‘, ‘G‘, ‘H‘, ‘J‘, ‘K‘, ‘L‘};
 6         Character[] row3 = {‘Z‘, ‘X‘, ‘C‘, ‘V‘, ‘B‘, ‘N‘, ‘M‘};
 7         List<Character> list1 = Arrays.asList(row1);
 8         List<Character> list2 = Arrays.asList(row2);
 9         List<Character> list3 = Arrays.asList(row3);
10         
11         for (String word : words) {
12             String newWord = word.toUpperCase();
13             
14             int i = 0, key = -1, n = newWord.length(); 
15             int counter1 = 0, counter2 = 0, counter3 = 0;
16             while (i < n) {
17                 if (list1.contains(newWord.charAt(i))) counter1++;
18                 else if (list2.contains(newWord.charAt(i))) counter2++;
19                 else if (list3.contains(newWord.charAt(i))) counter3++;
20                 
21                 i++;
22             }
23             
24             if (counter1 == n || counter2 == n || counter3 == n)
25                 result.add(word);
26         }
27         return result.toArray(new String[result.size()]);
28     }
29 }