#include<bits/stdc++.h>
using namespace std;
int main(){
	double a,b,c,d;
	cin>>a>>b>>c>>d;
	printf("%.2f %.2f %.2f",-b-2*sqrt(b*b-3*a*c)*cos(acos((2*b*(b*b-3*a*c)-3*a*(b*c-9*a*d))/(2*sqrt(pow(b*b-3*a*c,3))))),-b+sqrt(b*b-3*a*c)*(cos(acos((2*b*(b*b-3*a*c)-3*a*(b*c-9*a*d))/(2*sqrt(pow(b*b-3*a*c,3)))))+sqrt(3)*sin(acos((2*b*(b*b-3*a*c)-3*a*(b*c-9*a*d))/(2*sqrt(pow(b*b-3*a*c,3)))))),-b+sqrt(b*b-3*a*c)*(cos(acos((2*b*(b*b-3*a*c)-3*a*(b*c-9*a*d))/(2*sqrt(pow(b*b-3*a*c,3)))))-sqrt(3)*sin(acos((2*b*(b*b-3*a*c)-3*a*(b*c-9*a*d))/(2*sqrt(pow(b*b-3*a*c,3)))))));
	return 0;
}

代码长度577B，共8行。
有点丑（勿喷

$x_1=\frac{-b-2\sqrt{b^2-3ac}\cos(\frac{\operatorname{acos}(\frac{2b(b^2-3ac)-3a(bc-9ad)}{2\sqrt{(b^2-3ac)^3}})}{3})}{3a}$

$x_2=\frac{-b+\sqrt{b^2-3ac}(\cos(\frac{\operatorname{acos}(\frac{2b(b^2-3ac)-3a(bc-9ad)}{2\sqrt{(b^2-3ac)^3}})}{3})+\sqrt{3}\sin(\frac{\operatorname{acos}(\frac{2b(b^2-3ac)-3a(bc-9ad)}{2\sqrt{(b^2-3ac)^3}})}{3})}{3a}$

$x_3=\frac{-b+\sqrt{b^2-3ac}(\cos(\frac{\operatorname{acos}(\frac{2b(b^2-3ac)-3a(bc-9ad)}{2\sqrt{(b^2-3ac)^3}})}{3})-\sqrt{3}\sin(\frac{\operatorname{acos}(\frac{2b(b^2-3ac)-3a(bc-9ad)}{2\sqrt{(b^2-3ac)^3}})}{3})}{3a}$

公式有错马？求助！