BFS_LocalPolytree( UPRMatric,MaxNode )

function  UPRMatric = BFS_LocalPolytree( UPRMatric,MaxNode )

Dim = size( UPRMatric,2 );
Queue = zeros( 1,Dim );
Front = 1; End = 2;
Queue(1) = MaxNode;
VisitedNodes = zeros( 1,Dim );
% h3 = view(biograph( UPRMatric ))
while Front ~= End
      CurrentNode = Queue( Front );
      VisitedNodes( CurrentNode ) = 1;
      Front = QueueMove( Front,Dim );    
      for p = 1:Dim
          if p ~= CurrentNode && UPRMatric( p,CurrentNode ) ~= 0 && UPRMatric( CurrentNode,p ) ~= 0 && VisitedNodes( p ) == 0        
              UPRMatric( p,CurrentNode ) = 0;
              if VisitedNodes( p ) == 0
                  Queue( End ) = p;              
                  End = QueueMove( End,Dim ); 
              end
          end
          if p ~= CurrentNode && UPRMatric( CurrentNode,p ) ~= 0 && VisitedNodes( p ) == 0
              if VisitedNodes( p ) == 0
                  Queue( End ) = p;              
                  End = QueueMove( End,Dim ); 
              end
          end
      end
end

end

function Next = QueueMove( Current,Dim )
     Next = mod( Current,Dim+1 )+1;
end