ALGO Geometry

#include <iostream>
#include <utility>
#include <cmath>
using namespace std;

typedef long long ll;
typedef long double ld;

struct pt { /* == vector */
    ld x, y;
    ld pol () { return atan2(x,y); } ld mod () { return sqrt(x*x + y*y); }
    friend pt operator- (const pt& a, const pt& b) { return pt{a.x-b.x, a.y-b.y}; }
    friend pt operator+ (const pt& a, const pt& b) { return pt{a.x+b.x, a.y+b.y}; }
    friend ld operator* (const pt& a, const pt& b) { return  a.x*b.y - a.y*b.x;   } /* vector */
    friend ld operator/ (const pt& a, const pt& b) { return  a.x*a.y + b.y*b.x;   } /* scalar */
};

struct line {
    ld a, b, c;
    void norm () { ld z = hypot(a, b); a /= z, b /= z, c /= z; }
    line () {}
    line (ld x, ld y, ld z) : a(x), b(y), c(z) {}
    line (pt I, pt II) {
        pt d = II - I;
        a = d.y, b = - d.x;
        c = - (a*I.x + b*I.y);
        norm();
    }
    line perp (pt p) {
        return line{
            (const ld)(-b),
            (const ld)( a),
            (const ld) (b* p.x - a * p.y)
            };
    }
};

int main () {
    while (1) {
        ld a, b, c, d;
        cin>>a>>b>>c>>d;
        line l(pt{a,b}, pt{c,d});
        cout << l.a << ' ' << l.b << ' ' << l.c << endl;
        l = l.perp(pt{a,b});
        cout << l.a << ' ' << l.b << ' ' << l.c << endl;
    }
    return 0;
}