%!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

/deepeq {
    2 dict begin
    /a exch def
    /b exch def
    a type b type eq {
        a type /dicttype eq {
            a length b length eq {
                <<
                    a {
                        pop
                        true
                    } forall
                    b {
                        pop
                        true
                    } forall
                >>
                true exch
                {
                    pop
                    dup a exch known {
                        dup b exch known {
                            dup a exch get exch b exch get deepeq not {
                                pop false
                            } if
                        } {
                            false
                        } ifelse
                    } {
                        false
                    } ifelse
                } forall
            } {
                false
            } ifelse
        } {
            a type dup /arraytype eq exch /stringtype eq or {
                a length b length eq {
                    true
                    0 1 a length 1 sub {
                        dup a exch get exch b exch get deepeq not {
                            pop false
                            exit
                        } if
                    } for
                } {
                    false
                } ifelse
            } {
                a b eq
            } ifelse
        } ifelse
    } {
        false
    } ifelse
    end
} bind def

/apush.right { % [a b] c -> [a b c]
    exch
    [ exch aload length 2 add -1 roll ]
} bind def


% end included library code

/widestvalley {
    11 dict begin
    /a exch def
    /av 0 array def
    /ac 0 array def
    /l -1 def
    a {
        /v exch def
        v l eq {
            ac dup dup length 1 sub dup 3 1 roll
            get 1 add put
        } {
            /av av v apush.right def
            /ac ac 1 apush.right def
            /l v def
        } ifelse
    } forall
    /s 0 array def
    /e 0 array def
    /c 0 def
    0 1 av length 1 sub {
        /i exch def
        /peak false def
        i 0 eq i av length 1 sub eq or {
            /peak true def
        } if
        peak not {
            av i 1 sub get av i get lt
            av i get av i 1 add get gt and {
                /peak true def
            } if
        } if
        peak {
            /s s c apush.right def
            /e e c ac i get add 1 sub apush.right def
        } if
        /c c ac i get add def
    } for
    /out 0 array def
    0 1 s length 2 sub {
        /i exch def
        /v s i get def
        e i 1 add get s i get sub 1 add out length gt {
            /out a s i get dup e i 1 add get exch sub 1 add getinterval def
        } if
    } for
    out
    end
} bind def

(widestvalley) test.start
[1 5 5 2 8] widestvalley [5 5 2 8] deepeq test
[2 6 8 5] widestvalley [2 6 8] deepeq test
[9 8 13 13 2 2 15 17] widestvalley [13 13 2 2 15 17] deepeq test
[2 1 2 1 3] widestvalley [2 1 2] deepeq test
[1 3 3 2 1 2 3 3 2] widestvalley [3 3 2 1 2 3 3] deepeq test
test.end