function step3()
global i l r q Q Cosi;
Cosi ( i + 2 , r ( i + 2 ) + 1 ) = Q ( i + 1 , q ( i + 1 ) );   %把當前特征放回Cosi中
r ( i + 2 ) = r ( i + 2 ) + 1;
l = l - 1;
q ( i + 1 ) = q ( i + 1 ) - 1;

if ( l == 0 )
    step2();
else
    step3();
end
return;