нули и единицы

program z1;
    var a:array[1..7,1..7] of integer;
    i,j,l,r:integer;
    begin

    l:=1;
    r:=7;
    for i:=1 to 7 do begin
        for j:=1 to l-1 do begin //от 1 до l - 1 пишем 0
            a[i,j]:=0;
            write(a[i,j], ' ');
        end;
        for j:=l to r do begin //от l до r пишем 1
        a[i,j]:=1;
        write(a[i,j], ' ');
        end;
        for j:=r+1 to 7 do begin //от r до 7 пишем 0
            a[i,j]:=0;
            write(a[i,j], ' ');
        end;
        if i < 4 then
            begin
                l:=l+1;
                r:=r-1;
            end;
        if i >= 4 then
            begin
                l:=l-1;
                r:=r+1;
            end;

        writeln;
    end;
end.