LEM1 - COIN
Tác giả: hieult
Ngôn ngữ: C++
#include <stdio.h>
//#include <conio.h>
#include <math.h>
#define pi 3.1415926535898
long long a[10003],n;
double Bcos(double t)
{
double T=0;
for(int i=1;i<=n;i++)
T=T+acos(1-2*a[i]*a[i+1]/((a[i]+t)*(a[i+1]+t)));
return T;
}
main()
{
//freopen("LEM1.in","r",stdin);
scanf("%lld",&n);
for(int i=1;i<=n;i++)
scanf("%lld",&a[i]);
a[n+1] = a[1];
double u = 0.01,v = 1000000000;
while(v-u>0.0000001)
{
double r = (u+v)/2;
if(Bcos(r)<2*pi)
v=r;
else u = r;
}
printf("%.3lf",u);
//getch();
}