Maximum box gap

Question

Task

You have a row of numbered boxes, with some filled with items and some empty. Your job is to output the number of boxes from the first to the last box, inclusive, minus the number of boxes of the largest gap between two filled boxes.

Rules

Your program should handle up to 1000 boxes. Score = size of program in bytes. -50 if you don't use a built-in sorting functionality. -150 if you program in assembly :D All cases will have at least one gap.

Input is a list of n-th boxes that are filled. Standard loop-holes aren't allowed.

Sample Input

9, 5, 4, 2

Functions with a list as input are fine.

Sample Output

5

This is the number of boxes between the 2nd and 9th box, inclusive, subtracted by the number of boxes of the gap between the 5th and 9th box (8 - 3 = 5)

Answer 1

CJam, -19 -22 -23 (27 bytes - 50 bonus)

Vq~_:+,\&_(+]z{~-~:Xe>}/X+z

Try it online.

Example run

$ cjam box-gap.cjam <<< '[9 5 4 2]'; echo
5

How it works

V                              " V := 0                                          ";
 q~                            " Q := eval(input))                               ";
   _:+,                        " S := range(sum(Q))                              ";
       \&                      " T := S ∩ T          # Preserves the order of S. ";
         _(+                   " U := T[1:] + [T[0]]                             ";
            ]z                 " Z := zip(T, U)                                  ";
              {       }/       " for (X,Y) ∊ Z:                                  ";
               :-~:Me>         "   V := max(V, M := ~(X - Y))                    ";
                        M+z    " R := abs(V + M)                                 ";

Answer 2

CJam, -8 (43 42 bytes - 50 bonus)

l~:A{e>}*A{e<}*-)A{_A\-f{-z}{e<}*}%{e>}*(-

Using tips by @Dennis!

Try it online here

Input is like:

[9 5 4 2]

Answer 3

Mathematica, 44 bytes

f=Max@#-Min@#-Max[RotateLeft[l=Sort@#]-l]+2&

Defines a function that takes one argument in form of a list {9, 5, 4, 2}.

Answer 4

APL (Dyalog 14) (34 - 50 = -16)

{⎕ML←3⋄(1+V-⌊/⍵)-⌈/≢¨⊂⍨~⍵∊⍨⍳V←⌈/⍵}

This is a function that takes a list.

Or, for the same amount of characters:

⎕ML←3⋄(1+V-⌊/B)-⌈/≢¨⊂⍨~B∊⍨⍳V←⌈/B←⎕

This reads the list from the keyboard.

Answer 5

Python 2 - 54 (117104-50)

x=input()
M=max(x)-min(x)+1
X=['1']*M
for i in x:X[i-min(x)]='0'
print M-len(max("".join(X).split('0')))

A program that pretends that the buckets are real, then awkwardly splits them into groups. Takes input like 9,5,4,2.