text: Function which converts the input line to its perpendicular bisector . It also inputs the points whose mid - point lies on the bisector
code: void perpendicularBisectorFromLine ( pdd P , pdd Q , double & a , double & b , double & c ) { pdd mid_point = make_pair ( ( P . first + Q . first ) / 2 , ( P . second + Q . second ) / 2 ) ;