Circl

题面：

思路：

       模拟，几种情况依次判断

代码：

var i,j,n,ans,x1,x2,y1,y2:longint;
 x,y,r:array[1..100] of longint;
  f1,f2:array[1..100] of boolean;

begin

assign(input,'circle.in');
reset(input);
assign(output,'circle.out');
rewrite(output);

 read(n);

 for i:=1 to n do read(x[i]);
 for i:=1 to n do read(y[i]);
 for i:=1 to n do read(r[i]);

 readln(x1,y1,x2,y2);

 for i:=1 to n do
  begin
   if sqr(x[i]-x1)+sqr(y[i]-y1)<sqr(r[i]) then f1[i]:=true;
   if sqr(x[i]-x2)+sqr(y[i]-y2)<sqr(r[i]) then f2[i]:=true;
  end;

 for i:=1 to n do
  if f1[i]<>f2[i] then inc(ans);

 write(ans);

close(input);close(output);

end.