dev编译能过但是交上去显示编译失败:(

#include<iostream>
#include<cmath>
#include<cstdio>
#include<cstring>
using namespace std;

int a,b,c,d;

double f(double x)
{
	return a*x*x*x+b*x*x+c*x+d;
}

double ans(double x)
{
	int u=x+0.5;
	int dow=x-0.5;
	while(abs(f(x))>=0.01)
	{
		x=0.5*(u+dow);cout<<x<<endl;
		if(f(x)*f(u)<0)
		{
			down=x;
		}
		if(f(x)*f(u)>0)
		{
			up=x;
		}
		if(f(x)==0)break;
	}
	return x;
}

int main()
{
	cin>>a>>b>>c>>d;
	double x1,x2,x3;
	int a=0;
	for(int i=-99;i<=99;i++)
	{
		if(f(i-0.5)*f(i+0.5)<=0)
		{
			switch(a)
			{
				case 0:x1=i;x1=ans(x1);a++;break;
				case 1:x2=i;x2=ans(x2);a++;break;
				default:x3=i;x3=ans(x3);a++;break;
			}
		}
	}
	
	printf("%.2f %.2f %.2f",x1,x2,x3);
	return 0;
}