[Question]
  [
*This is a [cops-and-robbers](/questions/tagged/cops-and-robbers "show questions tagged 'cops-and-robbers'") challenge. Answer here if you are a cop (crossword maker), answer the [companion question](https://codegolf.stackexchange.com/q/40305/26997) if you are a robber (crossword solver). You may take on both roles.*
# Cops (Puzzlers)
Your task is to write a 10×10 [crossword puzzle](http://en.wikipedia.org/wiki/Crossword) where, instead of words or phrases, snippets of code are the solutions to clues. Each clue will be a nonempty sequence of characters such that running the snippet of code it refers to will print the sequence to stdout.
Your post must include three things:
1. Your **blank** 10×10 crossword grid, using `#` for *darks* (clue separators) and `_` for *lights* (cells to be filled in).
	* Every horizontal or vertical sequence of 2 or more lights (bounded by darks or the grid edge) is an entry you must write a clue for. For convenience you should number these in the usual way (left-to-right, top-to-bottom) by replacing the `_` at the start of each entry with a unique character identifier (e.g. 1, 2,..., A, B,...).
	* Your grid may have any number of darks.
	* Your grid may have any number of clues.
	* Horizontal entries are always read left-to-right and vertical ones top-to-bottom.
2. A list of clues that contains every entry in your crossword, down and across.
	* Clues must contain at least 1 and no more than 10 characters.
	* If your clues contain spaces make sure they are obvious when you format your post.
3. *Header* and *footer* code snippets, each 20 characters or less.
	* These run respectively before and after a solution snippet, and may help in renaming long built-ins and such.
The procedure for ensuring a clue matches its corresponding code snippet is:
1. Concatenate the header, the snippet, and the footer: `[header][snippet][footer]`.
2. Run this as a normal program (independent of past runs) and look at what was printed to stdout.
3. If this matches the clue the snippet is a valid solution.
For simplicity you may only use [printable ASCII](http://en.wikipedia.org/wiki/ASCII#ASCII_printable_characters) (hex codes 20 to 7E) throughout. The header and footer alone may also contain tabs and newlines.
### Additional Notes
* For any snippet, running `[header][snippet][footer]` should not take more than a minute on a [decent modern computer](https://teksyndicate.com/forum/general-discussion/average-steam-users-computer-specs/150190).
* You must specify your programming language (and version).
* You may not use any common hashing algorithms.
* You may not use external libraries.
* Everything in your code must be deterministic, time invariant, and not need a network connection.
* `#` and `_` may occur in snippets (or anywhere else).
* You may reveal some of the characters in the crossword as [COTO has done](https://codegolf.stackexchange.com/a/40309/26997). They still count as lights. Robbers are not required to use these, they are just nice hints.
### Example
A simple example using Python 3. Header: `p=print;t=5;`. No footer.
Unsolved grid:
```
##########
1___2___##
_###_#####
_###_#####
_###_#####
####_#####
####_#####
###3______
####_#####
####_#####
```
Clues:
```
ACROSS
1: 8
3: A!
DOWN
1: 7
2: 10
```
Valid solution:
```
##########
print(8)##
(###+#####
7###=#####
)###5#####
####;#####
####p#####
###p('A!')
####t#####
####)#####
```
# Robbers (Solvers)
Your task is to solve the crosswords posted by the cops. You must use the same exact programming language as the crossword was given in, but otherwise any solution that matches all the clues is valid.
You may not solve your own crosswords, and you may only attempt to answer each of the other crosswords once.
Remember to post your solutions in the [companion question](https://codegolf.stackexchange.com/q/40305/26997).
# Scoring
If a crossword is solved within 72 hours it is no longer in the running. Once a crossword has lasted unsolved for 72 hours it is considered immune and the creator may post the solution (by editing their post and marking it immune).
The winning cop is the user who submitted the immune crossword with the fewest darks (`#`). In case of ties the highest voted submission wins. The solution must be posted for the answer to be accepted.
The winning robber is the user who solves the most crosswords. The tie-breaker is their sum of up-votes in the [companion question](https://codegolf.stackexchange.com/q/40305/26997).
  
[Answer]
# JavaScript, 0 darks – immune
```
 __________
|123456789A|
|B         |
|C         |
|D         |
|E         |
|F         |
|G         |
|H         |
|I         |
|J         |
 ----------
```
Here is the solution for all of you:
```
 __________
|~709-51+90|
|-0x33-31&8|
|8-42^07*70|
|306%4+0x34|
|0xb1204%51|
|-1+2+x>h--|
|'4'*32>>07|
|Math.E>2.7|
|8/2-1-7*22|
|'6'-025036|
 ----------
```
```
Header: var h=8,x=5;console.log(
Footer: );
```
## Clues
```
Across
1. -671
B. 8
C. -460
D. 54
E. 33
F. false
G. 1
H. true
I. -151
J. -10776
Down
1. NaN
2. 15
3. "1131t2"
4. 64
5. -48
6. 49
7. 6
8. true
9. 8
A. 315
```
Let me know if you think there are any results that I miscalculated.
[Answer]
# CJam, 41 darks - [solved by Martin Büttner](https://codegolf.stackexchange.com/a/40329/16402)
No header, footer or reserved squares. Let me know of any potential bugs.
The solution I originally had in mind had no whitespace - it is not the one that Martin Büttner found.
## Board
```
#5###6#7__
#4_3____##
1##_#_#_#A
2____##_#_
_##_##9___
_##_#E#_#_
_#C#8_____
##_#_####_
##B_______
D__#_####_
```
## Clues
**Across**
```
2: [[4 3]]
4: 24717
7: 32
8: E
9: "" (there is ONE trailing space after the quotes)
B: "m
D: 124
```
**Down**
```
1: [2 2 2 3]
3: 3010936384
5: 2017
6: "18"
7: ' "\"\""
8: !{}
A: -3u3
C: -1
E: Stack: ""
```
Good luck!
[Answer]
# C - 26 darks, 5 reserved - solved by [feersum](https://codegolf.stackexchange.com/questions/40305/code-crosswords-solutions/40337#40337)
```
   Clue #          Reserved
+----------+     +----------+
|1_2__3_#4_|     |"      #  |
|_#_##_#5_#|     | # ## #  #|
|6___7_8___|     |      8   |
|_#_#9____#|     | # #     #|
|_#AB_#C___|     | #   #    |
|D_#E_____#|     |  #      #|
|_#F#_#_#_#|     | # # # # #|
|_#GH__#I__|     | #    #   |
|_##J_#K#_#|     | ##  # # #|
|L___#M____|     |2 * # _   |
+----------+     +----------+
```
### Header
```
z[4]={9};main(_){_=
```
### Footer
```
;printf("%d",_);}
```
### Clues
```
ACROSS:
1. 48
4. -8
5. -2
6. 0
9. 73
A. 9
C. 0
D. 5
E. 0
G. -2
I. 0
J. 0
L. 18
M. 6247483
DOWN:
1. 45
2. 7680
3. 22
4. -97
5. 0
7. -1073741824
8. 8
B. 0
F. 42
H. 0
K. -2
```
[Answer]
# MATLAB - 28 Darks
## Solved by [feersum](https://codegolf.stackexchange.com/a/40370/31019)
### Boards
```
  CLUE #         RESERVED
 __________      __________
|12 3 4 5  |    |    [     |
|# # # # ##|    |#s# # # ##|
|6   # #7 8|    |    # #   |
|# # # # # |    |# # # # # |
|9 A       |    |6  7  y   |
|#B  # # # |    |#   # # # |
|C         |    |        g |
|# # ### # |    |# # ### # |
|# # ##D # |    |# # ##  # |
|E         |    |d         |
 ¯¯¯¯¯¯¯¯¯¯      ¯¯¯¯¯¯¯¯¯¯
```
**Header**
```
g=4;o=magic(3);disp(
```
**Footer**
```
);
```
### Clues
**Across**
* 1 `2`
* 6 `-1i`
* 7 `eye(3)`
* 9 `0`
* B `sqrt(-1)`
* C `1/25000`
* D `0`
* E `[0;0;0]`
**Down**
* 2 `log(1i)`
* 3 `100`
* 4 `10^16`
* 5 `[2,2;2,2]`
* 8 `512`
* A `inv(1i)`
* D `zeros(3)`
Note that I've changed things up slightly in the clues for this puzzle. Since MATLAB outputs are invariably verbose (for example, even printing the imaginary unit `1i` exceeds 10 characters [`0 + 1.0000i`]) and change depending on the default output format, the clues are all simple expressions whose *displayed output is equivalent to that of the corresponding solutions*.
In other words, you can consider an actual clue to be `disp( CLUE )`, where `CLUE` is the 10-character-or-less clue in the above lists.
Hopefully Calvin doesn't mind. I don't believe this violates the spirit of the clue length rule, which is likely to prevent crossword builders from inserting extremely-hard-to-generate solutions (i.e. words).
### Key
```
    KEY
 __________
|max([1 2])|
|#s#1#0#*##|
|1i^3#*#o\o|
|#n#+#1#n#(|
|6 -7+eye&1|
|#(i)#1#s# |
|.1 ^ 5*(g)|
|#)#2### #^|
|#*#/##~2# |
|diag(-o)>3|
 ¯¯¯¯¯¯¯¯¯¯ 
```
[Answer]
# Python
## Solved by [feersum](https://codegolf.stackexchange.com/a/40421/4020)
Here's one to start us off. I used Python 2.7.8 to obtain the clues. Good luck :)
I've revealed the last snippet since hashing is now disallowed. Also, the grid has 36 darks (I missed the scoring part when I made it).
I've revealed a few more characters to make it easier, but different solutions are fine too.
Crossword grid:
```
1_234##5##         * . ## ##
_#6_______         #  e /   
_#7__##_##         # * ##6##
8________#        3   %    #
##_#_##_##        ##5# ## ##
#9________        #a   *   b
##_#_##_##        ## # ## ##
A________#        b   7  1 #
##_####_##        ## #### ##
#hash('9')        #hash('9')
```
Clues:
```
ACROSS
1: 440380.9
6: 12328.7671
7: 72
8: 4519217.0
9: 79920L
A: 1.55826556
B: 7296021944
DOWN
1: 1211477643
2: 17353.0
3: 5.4
4: 1719.0
5: 7514613.78
```
Header:
```
a=49481
b=97381
x=
```
Footer:
```
print`x`[:10]
```
[Answer]
# Javascript ES4 - 37 Darks, 10 Reserved
## Solved by [bazzarg](https://codegolf.stackexchange.com/a/40333/31019)
### Boards
```
   CLUE #         RESERVED
 __________      __________
|1  2 ###3#|    |     ### #|
| ## #45   |    | ## #I   4|
| ## ## # #|    |:##-## # #|
|6        #|    |         #|
| ## ## # #|    | ## ##.# #|
|7         |    |         ]|
| ## ## ###|    | ## ## ###|
|8   #9    |    | +  #   - |
| ## ## ###|    |'## ## ###|
| ##A      |    | ##   4   |
 ¯¯¯¯¯¯¯¯¯¯      ¯¯¯¯¯¯¯¯¯¯
```
**Header**
```
a=3;I=9;t=
```
**Footer**
```
;console.log(t);
```
### Clues
**Across**
* 1 `51`
* 4 `true`
* 6 `8.14159265` ...
* 7 `"90"`
* 8 `0`
* 9 `-10`
* A `"HI"`
**Down**
* 1 `5`
* 2 `"2pac"`
* 3 `3072`
* 5 `false`
Note that I've included a second representation of the board marked "reserved" to indicate ten lights with characters already filled in. These are to assist the solver and to restrict/disambiguate the possible solutions. I'm not sure whether Calvin wants to count these as darks or lights.
I've used the two separate representations since some of the filled-in characters are numbers and might be confused for clue numbers, and to declutter the board generally.
There are no whitespace characters in any of the solutions, although you're welcome to fill lights with whitespace characters if they work.
**Original Solution**
> 
> `__________
> |{},51###6#|
> |a##+#I/a<4|
> |:##-##[#<#|
> |5+Math.PI#|
> |}##+##.#+#|
> |[I+"0"][0]|
> |'##p##/###|
> |a+-a#a=~-I|
> |'##c##=###|
> |]##"\x48I"|
>  ¯¯¯¯¯¯¯¯¯¯`
> 
> 
> 
As it turns out, bazzarg's solution for 9 across has the `-` in the wrong place, but the clue was supposed to be `10` instead of `-10` (the clue and answer were originally different and I made the switch hastily). Hence we'll just say that two wrongs do make a right in this case. ;)
[Answer]
## Python 2, 0 darks - Immune
Python 2 is only because of the `print` in the footer. It should work the same way in Python 3 if you change the `print` statement.
I had fun making this, and overall I'm satisfied and a bit excited about the final result.
Let me know if you think my footer is too cruel (if I knew you could refrain from using a program to brute force it, I'd remove the cruelty.) Fun fact: the variables in the header spell 'bread'.
```
 __________
|123456789A|
|B         |
|C         |
|D         |
|E         |
|F         |
|G         |
|H         |
|I         |
|J         |
 ----------
```
**Header:** 
```
b=7;r=3;e=6;a=.1;d=
```
**Footer:** 
```
;print 2*str(d)[::3]
```
---
## Clues:
**Across**
```
1. 74
B. 282.e2
C. 77
D. 8
E. 94
F. 247351.862e1
G. 99
H. -5312-5312
I. -32
J. 300000
```
**Down**
```
1. 61000
2. 251
3. 09333.8333
4. 7878
5. -70
6. -0045.164
7. 88
8. 61225
9. -350
A. 69971
```
---
**Solution**
> 
>   `__________
>  |r+111-37-r|
>  |'2.48e+22'|
>  |6+765-0*56|
>  |30/7%140*2|
>  |0xe6b/0x27|
>  |18**+9.1-9|
>  |047--01551|
>  |04/-7.0131|
>  |0-1512%989|
>  |'30000700'|
>  ----------`
> 
> 
> 
]