LEM1 - COIN
Tác giả: ladpro98
Ngôn ngữ: Pascal
program lem1;
uses math;
const fi='';
maxn=10004;
eps=1e-4;
ok=360;
var a:array[0..maxn] of extended;
l,r,m,x,y,z,t,alpha:extended;
n,i:longint;
inp:text;
begin
assign(inp,fi);reset(inp);
readln(inp,n);
for i:=1 to n do read(inp,a[i]);
a[0]:=a[n];
l:=0;r:=1e9;
while (r-l>eps) do
begin
m:=(l+r)/2;
alpha:=0;
for i:=1 to n do
begin
x:=m+a[i-1];
y:=m+a[i];
z:=a[i-1]+a[i];
t:=arccos((sqr(x)+sqr(y)-sqr(z))/(2*x*y));
alpha:=alpha+radtodeg(t);
end;
if alpha<ok then r:=m
else l:=m;
end;
write(m:0:3);
end.