%!PS

% begin included library code
% see https://codeberg.org/Firedrake/postscript-libraries/
/test.start {
    print (:) print
    /test.pass 0 def
    /test.count 0 def
} 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 {
    /test.count test.count 1 add def
    {
        /test.pass test.pass 1 add def
    } {
        ( ) print
        test.count (....) cvs print
        (-fail) print
    } ifelse
} bind def


% end included library code

/sumdifference {
    0 dict begin
    0 exch
    {
        /x exch def
        x 10 ge {
            /digitsum 0 def
            /xa x def
            {
                xa 0 eq {
                    exit
                } if
                /digitsum digitsum xa 10 mod add def
                /xa xa 10 idiv def
            } loop
            x add digitsum sub
        } if
    } forall
    end
} bind def

(sumdifference) test.start
[1 23 4 5] sumdifference 18 eq test
[1 2 3 4 5] sumdifference 0 eq test
[1 2 34] sumdifference 27 eq test
test.end