题解 | 点到直线距离

double getDistance(point P, line L){
    int a=L.point_A.y-L.point_B.y;
    int b=L.point_B.x-L.point_A.x;
    int c=L.point_A.x*L.point_B.y-L.point_A.y*L.point_B.x;
    return(abs(static_cast<double>(a*P.x+b*P.y+c))/sqrt(static_cast<double>(a*a+b*b)));
}