private int getNumberSign(String s) {
    return s.charAt(0) == '+' ? 1 : -1;
  }
Iterative solution to this problem. The complexity order of this algorithm is O(N) because we
have to use split and is the most expensive operation. In space terms the complexity order is
O(N) and related directly to the size of the number in scientific notation.
src/main/java/com/github/pedrovgs/problem30/ScientificNotation.java