%!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

/rotor {
    5 dict begin
    /delta exch def
    /size exch def
    dup length /len exch def
    /ar exch def
    /ix 0 def
    [
        {
            ix size add len gt {
                exit
            } if
            ar ix size getinterval
            /ix ix size delta add add def
        } loop
    ]
    end
} bind def


% end included library code

/mingap {
    0 dict begin
    /a exch def
    /mg a dup length 1 sub get a 0 get sub def
    /mv 0 def
    a 2 -1 rotor {
        /p exch def
        /delta p 1 get p 0 get sub def
        delta mg lt {
            /mg delta def
            /mv p 1 get def
        } if
    } forall
    mv
    end
} bind def

(mingap) test.start
[2 8 10 11 15] mingap 11 eq test
[1 5 6 7 14] mingap 6 eq test
[8 20 25 28] mingap 28 eq test
test.end