According to the paper: "A Faster Algorithm for Betweenness Centrality", Ulrik Brandes had proposed on Journal of Mathematical Sociology. The node v should be predecessor of w (in bc_subquery.gsql is a and t), but in line 37 to 39, the direction is wrong, so I exchange s and t, then the result of betweenness centrality is correct.
According to the paper: "A Faster Algorithm for Betweenness Centrality", Ulrik Brandes had proposed on Journal of Mathematical Sociology. The node v should be predecessor of w (in bc_subquery.gsql is a and t), but in line 37 to 39, the direction is wrong, so I exchange s and t, then the result of betweenness centrality is correct.