mirror of
https://github.com/Kiritow/OJ-Problems-Source.git
synced 2024-03-22 13:11:29 +08:00
57 lines
1.5 KiB
C++
57 lines
1.5 KiB
C++
|
#include<iostream>
|
||
|
|
#include<cstdio>
|
||
|
|
#include<cstring>
|
||
|
|
#include<cmath>
|
||
|
|
using namespace std;
|
||
|
|
double a,b,c,d,L,R;
|
||
|
|
double f(double x)
|
||
|
|
{
|
||
|
|
return fabs(a*x*x*x+b*x*x+c*x+d);
|
||
|
|
}
|
||
|
|
const double eps=1e-9;
|
||
|
|
int dcmp(double x)
|
||
|
|
{
|
||
|
|
if(fabs(x)<=eps)return 0;
|
||
|
|
else return x<0?-1:1;
|
||
|
|
}
|
||
|
|
bool judge(double x)
|
||
|
|
{
|
||
|
|
return x<=R&&x>=L;
|
||
|
|
}
|
||
|
|
int main()
|
||
|
|
{
|
||
|
|
while(scanf("%lf%lf%lf%lf%lf%lf",&a,&b,&c,&d,&L,&R)!=EOF)
|
||
|
|
{
|
||
|
|
double delta=4*b*b-12*a*c;
|
||
|
|
double ans;
|
||
|
|
if(dcmp(a)==0)
|
||
|
|
{
|
||
|
|
double mid=-c/2/b;
|
||
|
|
if(judge(mid))
|
||
|
|
ans=max(f(mid),f(L));
|
||
|
|
else ans=f(L);
|
||
|
|
ans=max(ans,f(R));
|
||
|
|
}
|
||
|
|
else if(delta<=0)
|
||
|
|
{
|
||
|
|
ans=max(f(L),f(R));
|
||
|
|
}
|
||
|
|
else
|
||
|
|
{
|
||
|
|
delta=sqrt(delta);
|
||
|
|
double x1=-2*b+delta;
|
||
|
|
x1=x1/6/a;
|
||
|
|
double x2=-2*b-delta;
|
||
|
|
x2=x2/6/a;
|
||
|
|
ans=f(L);
|
||
|
|
ans=max(ans,f(R));
|
||
|
|
if(judge(x1))
|
||
|
|
ans=max(ans,f(x1));
|
||
|
|
if(judge(x2))
|
||
|
|
ans=max(ans,f(x2));
|
||
|
|
}
|
||
|
|
printf("%.2lf\n",ans);
|
||
|
|
}
|
||
|
|
return 0;
|
||
|
|
}
|