/// <summary>
/// Gets the heuristic value for the given relative state (in the context of backward search).
/// </summary>
/// <param name="relativeState">Relative state to be evaluated.</param>
/// <returns>Heuristic value for the specified relative state.</returns>
protected override double GetValueImpl(IRelativeState relativeState)
{
return(1.0 / relativeState.GetSize());
}