记录编号	7261	评测结果	AAWWWWWWWA
题目名称	放养奶牛	最终得分	30
用户昵称	苏轼	是否通过	未通过
代码语言	Pascal	运行时间	0.038 s
提交时间	2008-11-07 17:42:12	内存使用	0.17 MiB

program cch(input,output);
const
 maxf=10000000000000;
type
 sz=record
    x:array[1..40] of integer;
    y:array[1..40] of integer;
    num:integer;
    end;
var
 i,n,j,s,k:integer;
 a:array[1..101] of sz;
 f:array[1..101,1..40] of real;
 b:array[1..101,1..40] of integer;
 tmp,ans:real;

function check(c,h,k:integer):boolean;
var
 i,j:integer;
begin
 if (a[c].x[h]=a[c-1].x[k])and(a[c].y[h]=a[c-1].y[k]) then exit(false);
 j:=k;
 for i:=c-1 downto 2 do
  begin
   j:=b[i,j];
   if (a[c].x[h]=a[i-1].x[j])and(a[c].y[h]=a[i-1].y[j]) then exit(false);
  end;
 exit(true);
end;

begin
 assign(input,'cowties.in');
 assign(output,'cowties.out');
 reset(input);
 rewrite(output);
 readln(n);
 for i:=1 to n do
  begin
   read(s);
   for j:=1 to s do read(a[i].x[j],a[i].y[j]);
   a[i].num:=s;
  end;
 for i:=1 to 40 do f[1,i]:=0;
 for i:=2 to n do
  for j:=1 to a[i].num do
   begin
    f[i,j]:=maxf;
    for k:=1 to a[i-1].num do
     begin
      tmp:=f[i-1,k]+sqrt(sqr(a[i-1].x[k]-a[i].x[j])+sqr(a[i-1].y[k]-a[i].y[j]));
      if (tmp<f[i,j]) and check(i,j,k) then
       begin
        f[i,j]:=tmp; b[i,j]:=k;
       end;
     end;
   end;
 for i:=1 to a[n].num do
  begin
   k:=i;
   for j:=n downto 2 do k:=b[j,k];
   f[n,i]:=f[n,i]+sqrt(sqr(a[1].x[k]-a[n].x[i])+sqr(a[1].y[k]-a[n].y[i]));
  end;
 ans:=maxf;
 for i:=1 to a[n].num do
  if ans>f[n,i] then
   ans:=f[n,i];
 write(trunc(ans*100));
 close(input);
 close(output);
end.