const
  n = 10;
type
  arrType = array[1 .. n] of integer;

procedure f(var arr: arrType; X: integer; is_odd: boolean; level: integer);
const
  odd_start: integer = n div 2;
  even_start: integer = n;
begin
  if level <= n then f(arr, arr[level], odd(level), succ(level));

  if is_odd then begin
    arr[odd_start] := X; dec(odd_start);
  end
  else begin
    arr[even_start] := X; dec(even_start);
  end;
end;

const
  // неважно, можно и ввод организовать...
  arr: arrType = (31, 32, 33, 34, 35, 36, 37, 38, 39, 40);

var i: integer;

begin
  f(arr, arr[1], true, 2);
  for i := 1 to n do write(arr[i]:4);
  writeln;
end.

const
  n=18;
  n2=n div 2;

type
  tElem=integer;

var
  i,j:integer;
  w:array[1..n] of tElem;
  a,b:tElem;

begin
  for j:=1 to n do w[j]:=j;

  for i:=1 to n2 div 2+1 do begin
    WriteLn('i=',i);
    for j:=1 to n do Write(w[j]:4); WriteLn;
    a:=w[i+1];
    b:=w[n-i];
    for j:=i+1 to n2-i do w[j]:=w[j+1];
    for j:=n-i-1 downto n2+i do w[j+1]:=w[j];
    w[n2+i]:=a;
    w[n2-i+1]:=b;
  end;
  ReadLn
end.

const
  n=16;
  n2=n div 2;

type
  tElem=integer;

var
  i,j:integer;
  w:array[1..n] of tElem;
  a,b:tElem;

begin
  for j:=1 to n do w[j]:=j;

  for i:=1 to n2 div 2 do begin
    a:=w[i+1];
    b:=w[n-i];
    for j:=i+1 to n2-i do w[j]:=w[j+1];
    for j:=n-i-1 downto n2+i do w[j+1]:=w[j];
    w[n2+i]:=a;
    w[n2-i+1]:=b;
  end;
  for j:=1 to n do Write(w[j]:4); WriteLn;
  ReadLn
end.

uses crt;
const
   n=10;
var
   mas:array[1..n] of byte;
   i,buf:byte;
begin
clrscr;
for i:=1 to n do
    if (i mod 2)=0 then
       mas[i]:=0
    else
       mas[i]:=1;

for i:=1 to n do
   write(mas[i],' ');
writeln;

{------------Главный цикл--------------------------}
for i:=1 to (n div 2) do
    if (i mod 2)=0 then
       begin
            buf:=mas[i+n div 2];
            mas[i+n div 2]:=mas[i];
            mas[i]:=buf;
       end;
{---------------------------------------}
for i:=1 to n do
   write(mas[i],' ');
readln;
end.

uses crt;
const n=10;
type arr=array [1..n] of byte;
var x:array [1..n] of byte;
i,q:integer;
begin
clrscr;
for i:=1 to n do x[i]:=i;
for i:=1 to n do write (x[i]:3); writeln; 
for i:=1 to n div 2 do begin
q:=x[i]; x[i]:=x[(I-1)*2+1]; x[(i-1)*2+1]:=q;
end;
for i:=1 to n do write (x[i]:3); writeln;
end.

program mas;
const n=15;
var arr: array [1..n] of integer;
i,dop,b,a:integer;
begin
randomize;
for i:=1 to n do
  begin
  arr[i]:=i;
  write(' ',arr[i]);
  end;
writeln;
if odd(n) then
 begin
 b:=n+1;
 a:=n div 2+1;
 end
else
 begin
 b:=n;
 a:=n div 2;
 end;
for i:=1 to a do
  if not(odd(i)) then
    begin
    dop:=arr[i];
    arr[i]:=arr[b-i+1];
    arr[b-i+1]:=dop;
    end;
for i:=1 to n do
  write(' ',arr[i]);
writeln;
writeln;
readln;
end.