public static void main(String[] args) {

String s = "23#(2)24#25#26#23#(3)";

int[] result = frequency(s);

System.out.println(Arrays.toString(result));

}

private static int[] frequency(String s) {

int[] result = new int[26];

int size = s.length();

int i = 0;

while (i < size) {

int val = 0;

if (i + 2 >= size || s.charAt(i+2) != '#') {

val = s.charAt(i) - '0';

result[val - 1]++;

i++;

} else if (s.charAt(i+2) == '#'){

val = (s.charAt(i) - '0') * 10 + (s.charAt(i + 1) - '0');

result[val - 1]++;

i = i+3;

}

if (i < size) {

if (s.charAt(i) == '(') {

int frequen = s.charAt(i+1) - '0';

result[val-1] += frequen - 1;

i = i + 3;

}

}

}

return result;

}