/** execution method of event handler */
static
SCIP_DECL_EVENTEXEC(eventExecBacktrack)
{  /*lint --e{715}*/
   /* if current node is leaf*/
   if ( SCIPeventGetType(event) & SCIP_EVENTTYPE_BACKTRACK )
   {
    SCIP_EVENTHDLRDATA*	eventhdlrdata;
    eventhdlrdata = SCIPeventhdlrGetData( eventhdlr );
    assert ( eventhdlrdata != NULL );

    SCIP_NODE* 	node;
    int		depth;

    node = SCIPeventGetNode( event );
    depth = SCIPnodeGetDepth( node );

    eventhdlrdata->numerator 		= 	2-(2^-depth);
    eventhdlrdata->denominator	=	2^(-depth);
    eventhdlrdata->leaves 		= eventhdlrdata->leaves + 1;

    printf( "Current Estimate: %.1f\n", eventhdlrdata->numerator / eventhdlrdata->denominator );
    printf( "Leaves encountered: %.1f\n", eventhdlrdata->leaves );

   }
   return SCIP_OKAY;
}