ac1104.pas

同济大学 Online在线题库 AC源代码合集 程序设计竞赛必看资料

program tju1104;
const
  maxr=100;
var
  x1,x2,y1,y2:array[1..maxr]of word;
  l:array[1..maxr*2]of word;
  b:array[1..maxr*2]of boolean;
  r,i,t:word;
  sum:longint;
procedure qsort(s,t:word);
  var
    p,i,j,tl:word;
    tb:boolean;
  begin
    if s>=t then exit;
    p:=s+random(t-s+1);
    tl:=l[p];tb:=b[p];l[p]:=l[s];b[p]:=b[s];
    i:=s;j:=t;
    repeat
      while (i<j) and (l[j]>=tl) do dec(j);
      if i=j then break;l[i]:=l[j];b[i]:=b[j];inc(i);
      while (i<j) and (l[i]<=tl) do inc(i);
      if i=j then break;l[j]:=l[i];b[j]:=b[i];dec(j);
    until i=j;
    l[i]:=tl;b[i]:=tb;
    qsort(s,i-1);
    qsort(i+1,t);
  end;
procedure cal_one(u,v,h,x:word);
  var
    c,i,s:word;
  begin
    c:=0;
    for i:=1 to r do
      if ((y1[i]<h) or (y1[i]=h) and (i<x)) and (y2[i]>=h) and (x1[i]<v) and (x2[i]>u) and (i<>x) then begin
        inc(c);if x1[i]<u then l[c]:=u else l[c]:=x1[i];b[c]:=true;
        inc(c);if x2[i]>v then l[c]:=v else l[c]:=x2[i];b[c]:=false;
      end;
    qsort(1,c);
    h:=0;s:=0;
    for i:=1 to c do
      if b[i] then begin
        if h=0 then x:=l[i];inc(h);
      end
      else begin
        dec(h);if h=0 then inc(s,l[i]-x);
      end;
    inc(sum,v-u-s);
  end;
procedure cal_all;
  begin
    for i:=1 to r do
      cal_one(x1[i],x2[i],y1[i],i);
  end;
begin
  repeat
    read(r);
    for i:=1 to r do
      read(x1[i],x2[i],y1[i],y2[i]);

    sum:=0;
    cal_all;
    for i:=1 to r do begin
      t:=x1[i];x1[i]:=y1[i];y1[i]:=t;
      t:=x2[i];x2[i]:=y2[i];y2[i]:=t;
    end;
    cal_all;
    writeln(sum*2);
  until seekeof;
end.