Count the unique character in a String

count.java

// Author: Mahbub
// http://mahbubzaman.wordpress.com/2012/06/21/count-the-unique-character-in-a-string/
/*
input
“aaaaaa”
“aaa aaa”
“abcdeabcde”
“YESyes”

output
1
2
5
6
*/

public static int frq [] = new int [500];    
public static int countUniqueChar (String line) {
      Arrays.fill(frq, 0);
      int ans = 0;
      for(int i = 0; i < line.length(); ++i) {
          if(frq[line.charAt(i)] == 0) {
              frq[line.charAt(i)]++;
              ++ans;
          }
      }
      return ans;
}