// Salida:
// 1
// 0
// 3

public class EnigmaDos {

   public static int enigma(String[] vector, String valor) {
      return enigma(vector, valor, 0, vector.length - 1);
   }

   private static int enigma(String[] vector, String valor, int a, int b) {
      int aux = 0;
      if (a > b)
         return 0;
      if (vector[a].equals(valor))
         aux++;
      if (a != b && vector[b].equals(valor))
         aux++;
      return aux + enigma(vector, valor, a + 1, b - 1);
   }

   public static void main(String[] args) {
      String[] letras = { "a", "g", "c", "g", "b", "c" };
      System.out.println(enigma(letras, "b"));
      System.out.println(enigma(letras, "e"));

      String[] vocales = { "o", "e", "o", "e", "o" };
      System.out.println(enigma(vocales, "o"));
   }

}