LeetCode: Detect Capital

這裏利用'A'到'Z'都小於'a'到'z'

 1 public class Solution {
 2     public boolean detectCapitalUse(String word) {
 3         int num = 0;
 4         for (char c : word.toCharArray()) {
 5             if ('Z' - c >= 0) {
 6                 num++;
 7             }
 8         }
 9         if (num == 0 || num == word.length()) return true;
10         if (num == 1  && 'Z' - word.charAt(0) >= 0) return true;
11         return false;
12     }
13 }