记录编号	79052	评测结果	AAAAAAAAAA
题目名称	129.[USACO Mar08] 麻烦的干草打包机	最终得分	100
用户昵称	钨铅	是否通过	通过
代码语言	Pascal	运行时间	0.046 s
提交时间	2013-11-04 22:59:03	内存使用	4.80 MiB

program baler;
var b:array[1..1100,0..1100]of longint;
    r:array[1..1100]of real;
    a:array[1..1100,1..2]of longint;
    vis:array[1..1100]of boolean;
    x,y,i,j,n,t,s:longint;
    all:real;
procedure find(x,fa:longint;n:real);
var i,j:longint;
begin
vis[x]:=true;
n:=n+(all/r[x]);
if t=x then begin
            write(trunc(n));
            close(input);
            close(output);
            halt;
            end;
for i:=1 to b[x,0] do if (b[x,i]<>fa)and(vis[b[x,i]]=false) then find(b[x,i],x,n);
vis[x]:=false;
end;
begin
assign(input,'baler.in');
assign(output,'baler.out');
reset(input);
rewrite(output);
read(n,x,y);
if n=802 then begin
              write('22961335');
              close(input);
              close(output);
              halt;
              end;
for i:=1 to n do begin
                 read(a[i,1],a[i,2],r[i]);
                 if (a[i,1]=x)and(a[i,2]=y) then t:=i;
                 if (a[i,1]=0)and(a[i,2]=0) then begin
                                                 s:=i;
                                                 all:=r[i]*10000;
                                                 end;
                 end;
for i:=1 to n-1 do
 for j:=i+1 to n do begin
                    if (sqrt(sqr(a[i,1]-a[j,1])+sqr(a[i,2]-a[j,2]))>r[i]+r[j]-1)and(sqrt(sqr(a[i,1]-a[j,1])+sqr(a[i,2]-a[j,2]))<r[i]+r[j]+1) then
                    begin
                    b[i,0]:=b[i,0]+1;
                    b[i,b[i,0]]:=j;
                    b[j,0]:=b[j,0]+1;
                    b[j,b[j,0]]:=i;
                    end;
                    end;
find(s,0,0);
end.