/// <summary>
/// Executes once at the start of the iteration and before the End() method
/// Initializes the iterator variable ( realized in the subclasses ) and the
/// m_currentItem to point to the first element of the item set. If the set is
/// empty the m_currentItem points to null. After the Begin() method the
/// End() method executes before going into the loop body. Thus the loop
/// terminates if the item set is empty before ever running the loop body
/// The transition logic for finding the first item in the items set is
/// implemented in the subclasses
/// </summary>
/// <returns></returns>
public override CGraphNode Begin()
{
m_it = 0;
m_iterations = 0;
m_currentItem = null;
while (m_it < m_graph.M_NumberOfNodes && // while not search all the nodes AND...
m_graph.Node(m_it).M_NumberOfSuccessors != 0) // while not discover nodes without successors
{
m_it++;
}
if (m_it < m_graph.M_NumberOfNodes)
{
m_currentItem = m_graph.Node(m_it);
return(m_currentItem);
}
return(m_currentItem);
}
/// <summary>
/// Points to the first valid item if to null if there is no one
/// </summary>
/// <returns></returns>
public override CGraphNode Begin()
{
m_it = 0;
m_iterations = 0;
m_lastItem = false;
if (m_graph.M_NumberOfNodes > 0)
{
m_currentItem = m_graph.Node(m_it);
if (m_graph.M_NumberOfNodes == 1)
{
m_lastItem = true;
}
}
else
{
m_currentItem = null;
}
return(m_currentItem);
}
