CRUELL2 - Cô giáo dạy toán, phần II
Tác giả: RR
Ngôn ngữ: Pascal
{$R+,Q+}
uses math;
const
FINP='';
FOUT='';
eps=0.00001;
var
x,temp,left,right,mid:double;
a:array[0..11] of double;
n:longint;
function cal(x:double):double;
var
i:longint;
kq:double;
begin
kq:=0;
for i:=n downto 0 do
kq:=kq*x+a[i];
exit(kq);
end;
begin
assign(input,FINP); reset(input);
assign(output,FOUT); rewrite(output);
read(n);
for n:=0 to n do read(a[n]);
left:=-1000000; right:=-left; x:=cal(left);
repeat
mid:=(left+right)/2;
temp:=cal(mid);
if abs(temp)<eps then begin writeln(trunc(mid*1000)); exit; end
else
if temp*x<0 then right:=mid
else left:=mid;
until left>right;
close(input); close(output);
end.