记录编号	394084	评测结果	AAAAAAAAAA
题目名称	树	最终得分	100
用户昵称	卍	是否通过	通过
代码语言	Pascal	运行时间	1.313 s
提交时间	2017-04-12 22:19:07	内存使用	49.76 MiB

type treed=record
  l,r,x:longint;
  end;
var
  r:real;
  tree:array[0..4000000]of treed;
  a:array[0..1000000]of longint;
  x,y,i,j,k,n,m:longint;
  procedure make(l,r,x:longint);
    var
      mid:longint;
    begin
      tree[x].l:=l; tree[x].r:=r;
      if l=r then tree[x].x:=a[l];
      if l<>r then
        begin
          mid:=(l+r)shr 1;
          make(l,mid,x shl 1);
          make(mid+1,r,(x shl 1)+1);
          tree[x].x:=tree[x shl 1].x+tree[(x shl 1)+1].x;
        end;
    end;
  function sum(x,y,z:longint):longint;
    var
      mid:longint;
    begin
      if x>y then exit(0);
      if (x=tree[z].l)and(y=tree[z].r) then exit(tree[z].x);
      mid:=(tree[z].l+tree[z].r)shr 1;
      if mid<x then sum:=sum(x,y,(z shl 1)+1)
      else if mid>=y then sum:=sum(x,y,z shl 1)
      else sum:=sum(x,mid,z shl 1)+sum(mid+1,y,(z shl 1)+1);
    end;
  procedure delete(mm,z,x:longint);
    var mid:longint;
    begin
      tree[z].x:=tree[z].x-x;
      if tree[z].l=tree[z].r then exit;
      if tree[z shl 1].r>=mm then delete(mm,z shl 1,x) else delete(mm,(z shl 1)+1,x);
    end;
begin
  assign(input,'treed.in'); assign(output,'treed.out');
  reset(input); rewrite(output);
  readln(n);
  for i:=1 to n do read(a[i]);
  make(1,n,1);
  readln(m);
  for i:=1 to m do
    begin
      read(x,y);
      r:=sum(x,y,1)*3.14;
      writeln(r:0:2);
      delete((x+y)shr 1,1,a[(x+y)shr 1]);
      a[(x+y)shr 1]:=0;
    end;
  close(input); close(output);
end.