%!PS

% begin included library code
% see https://github.com/Firedrake/postscript-libraries/
/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

/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

/pennypiles {
    dup 0 eq {
        1 exch pop
    } {
        4 dict begin
        /s 0 def
        /j exch 1 sub def
        /k 2 def
        {
            j 0 lt {
                exit
            } if
            /t j pennypiles def
            /s s t
            k 2 idiv 2 mod 0 eq {
                neg
            } if
            add def
            /j j
            k 2 mod 1 eq {
                k
            } {
                k 2 idiv
            } ifelse
            sub def
            /k k 1 add def
        } loop
        s
        end
    } ifelse
} bind def

(pennypiles) test.start
5 pennypiles 7 eq test
10 pennypiles 42 eq test
test.end