void setup() {
  println(editDist("apple", "bapple"));
}

int editDist(String a, String b) {
  // base cases
  // note: getting string length: https://www.tutorialspoint.com/java/java_string_length.htm
  if (a.length() == 0) {
    return b.length();
  } else if (b.length() == 0) {
    return a.length();
  } else {
    // figuring out if last characters are equal
    // note: getting character at specific position in string: https://www.tutorialspoint.com/java/java_string_charat.htm
    int x = 0;
    if (a.charAt(a.length() - 1) != b.charAt(b.length() - 1)) {
      x = 1;
    }
    // note: getting a new string without last character: https://www.tutorialspoint.com/Java-String-substring-Method-example
    return min(
      editDist(a.substring(0, a.length() - 1), b) + 1,  // deletion
      editDist(a, b.substring(0, b.length() - 1)) + 1,   // insertion
      editDist(a.substring(0, a.length() - 1), b.substring(0, b.length() - 1)) + x  // substitution
     );
  }
}