main.dart

void main(){
  print(fib(5));
  print(fibCached(100));
}

int fib(input) {
  if (input == 0) {
    return 0;
  } else if (input == 1) {
    return 1;
  }
  return fib(input - 1) + fib(input - 2);
}

int fibCached(input) {
    int helper(int n, [a = 0, b = 1]) {
        if (n == 0) {
            return a;
        } else {
            return helper(n - 1, b, a + b);
        }
    }

    if (input == 0) {
        return 0;
    } else {
        return helper(input);
    }
}