%!PS

% begin included library code
% see https://codeberg.org/Firedrake/postscript-libraries/
/s2a {
    [ exch { } forall ]
} bind def

/test.end {
    ( ) print
    test.count 0 gt {
        (Passed ) print
        test.pass (...) cvs print
        (/) print
        test.count (...) cvs print
        ( \() print
        test.pass 100 mul test.count idiv (...) cvs print
        (%\)) print
        (\r\n) print
    } if
} bind def

/test.start {
    print (:) print
    /test.pass 0 def
    /test.count 0 def
} bind def

/filter { % array proc(bool) -> array
    1 dict begin
    /p exch def
    [ exch
      {
          dup p not
          {
              pop
          } if
      } forall
    ]
    end
} bind def

/values { % dict -> array of dict values
    [ exch
      {
          exch pop
      } forall
    ]
} bind def

/test {
    /test.count test.count 1 add def
    {
        /test.pass test.pass 1 add def
    } {
        ( ) print
        test.count (....) cvs print
        (-fail) print
    } ifelse
} bind def

/enumerate.array {
    1 dict begin
    /a exch def
    [
      0 1 a length 1 sub {
          [ exch dup a exch get ]
      } for
    ]
    end
} bind def


% end included library code

/ballsandboxes {
    0 dict begin
    /boxes 0 dict def
    /colour 64 def
    s2a enumerate.array {
        aload pop
        /c exch def
        /i exch def
        i 2 mod 0 eq {
            /colour c def
        } {
            /boxid c 48 sub def
            /s 1 dict def
            boxes boxid known {
                /s boxes boxid get def
            } if
            s colour true put
            boxes boxid s put
        } ifelse
    } forall
    boxes values { length 3 ge } filter length
    end
} bind def

(ballsandboxes) test.start
(G0B1R2R0B0) ballsandboxes 1 eq test
(G1R3R6B3G6B1B6R1G3) ballsandboxes 3 eq test
(B3B2G1B3) ballsandboxes 0 eq test
test.end