Sandbox for Proposed Challenges

Question

This "sandbox" is a place where Code Golf users can get feedback on prospective challenges they wish to post to main. This is useful because writing a clear and fully specified challenge on your first try can be difficult, and there is a much better chance of your challenge being well received if you post it in the sandbox first.

Sandbox FAQ

Posting

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Write your challenge just as you would when actually posting it, though you can optionally add a title at the top. You may also add some notes about specific things you would like to clarify before posting it. Other users will help you improve your challenge by rating and discussing it.

When you think your challenge is ready for the public, go ahead and post it, and replace the post here with a link to the challenge and delete the sandbox post.

Discussion

The purpose of the sandbox is to give and receive feedback on posts. If you want to, feel free to give feedback to any posts you see here. Important things to comment about can include:

• Parts of the challenge you found unclear
• Comments addressing specific points mentioned in the proposal
• Problems that could make the challenge uninteresting or unfit for the site

You don't need any qualifications to review sandbox posts. The target audience of most of these challenges is code golfers like you, so anything you find unclear will probably be unclear to others.

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Other

Search the sandbox / Browse your pending proposals

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Answer 1

Triangularity

This is a challenge where you have to work out the length of a given w and h.

To qualify as a correct solution:

1. The program uses STDIN to get the values of w and h.
2. The program uses STDOUT to output the value of a in the above diagram.

The shortest code in bytes wins.

Tags: code-golf, maths

Answer 2

Wildcard Golf

Introduction

I've read this problem long time ago somewhere but I still don't know what's the best solution, so I'm posting it here. I don't remember the original author or wording so here is all in my own words.

This is different from regex golf because only two wildcards, * (equivalent to the regex .*) and ? (equivalent to the regex .), are allowed.

Challenge

You are given two lists of strings. You need to generate the shortest wildcard that matches all strings in the first list (the wanted-list) and none in the second list (the unwanted-list). In the wildcard, you can use * to match 0 or more chars and use ? to match any one char.

For simplicity we can assume that inputs only have lowercase English characters and each string won't be longer than 100 characters. But the list can be very long (like several thousand), so speed of your program is important.

The correct answer that has the lowest average-case theoretic time complexity wins. In a tie, an easier-to-read answer wins.

Example Input and Output

Input:

• Wanted list: abacum, academ, alarm, adam
• Unwanted list: alien, african, atom

One possible output: a?a*

I'd also like to hear about how to approach this problem, and how to prove the theoretic lower bound of time/space complexity.

---

I'm new to this so comments are welcome. I'm not sure if my winning criteria is clear and practical. Also I don't know what tags I should put there. This is not a code-golf question.

Answer 3

C++ Expression Matching

code-challenge c++ arithmetic

So, I like C++. And I like regex matching puzzles (heck, "regex golf" is what first got me lurking on this site). Might as well try to sort of combine the two!

Rules

Write a full program that takes as input two lists of zero to five integers in the range [1, 127], and outputs a string representation of a C expression that evaluates to nonzero / true for all integers in the first list, and zero / false for all integers in the second list. Input can be taken in any convenient form.

As a special case, if the second list is empty, then the expression returned must evaluate to true for only the integers in the first list, and false for all other integers in the range [1, 127]. Likewise, if the first list is empty, it should evaluate to false for the integers in the second list, and true for all others in that range.

The program will not receive two empty lists as input. If both lists are non-empty, there are no requirements on the result of the output when evaluated with an integer not in the input. (any return value is fine, as is undefined behavior, division by 0, etc).

The following tokens may be used in the expression:

• Integer literals in decimal, hex, or octal, with optional U and/or LL suffix to denote unsigned / long long ints.
• A single int variable, which will contain each of the integers from the input in turn. The variable can have any legal variable name.
• Any of the unary operators + - ! ~
• Any of the binary operators + - * / % << >> < > <= >= == != & | ^ && || ,
• The ternary operator ?:
• Parentheses.
• Operators that mutate their arguments (++ --, = += -= etc.) are not allowed.
• Character literals ('a', '_', '\0', etc.) are not allowed.

Some examples of possible outputs:

true            false           sample expression
[1, 3, 5, 7],   [2, 4, 6, 8]    c%2
[5, 6, 10],     [2, 8, 16]      t&~-t
[7, 14, 21],    []              22>x&!(x%7)

(TODO: Specify undefined / implementation-defined behavior details? My test program assumes 32-bit ints / longs, 64-bit long longs, and "nice" two's-complement signed overflow / conversion.)

This challenge is code-challenge; your score is determined by the total number of characters in the outputs for these ten randomly-generated inputs: (TODO).

Bonus: Subtract 15 from your score if the output expression evaluates to 1, not just nonzero, for all 'true' inputs.

Sandbox Questions

Welp, turns out my "Round Fractions" question from earlier is pretty much a subset of "Closest fraction". So here's another idea I've been tossing around since the one challenge I answered in C a while back (Area of an ASCII Polygon).

This is still very much a work-in-progress spec, though; some questions I have:

• I believe this could be tagged as C rather than C++; the only difference I'm aware of is the ternary conditional's precedence, and given that no assignment operators are allowed, it might not make a difference.
• I'm not sure what tags would go best on this (is it kolmogorov-complexity if the output isn't fixed?)
• I imagine there should probably be some additional constraint to prevent theoretically optimal but impossibly slow brute-force searches.
• The range [1, 127] is kind of arbitrary; my thought is that it should be able to handle anything in ASCII range + whitespace characters, but not much more than that, so as to make the special cases less restrictive.
• Would there be a way to spin this off as code-golf, if establishing run-time conditions is too arbitrary?

I'm mostly done writing a program to test the output expressions; just need to do a bit more testing.

That's pretty much it; hopefully this is enough to work with for feedback. Thoughts / comments?

Answer 4

Typographic Chemistry

Inspired by this: https://xkcd.com/1442/

Task

You must make a program or function that take input a string from STDIN and output the possible allowed reactions (1 point per unique reaction, see also "Score" below)

Rules

A chemical reaction is allowed if all the "legs" of the elements are used, i.e., there are no unpaired "legs". A "leg" is just the end of a curve in the typographic print of the chemical symbol (see the comic and it should be clear). So for example:

Carbon - C - 2 legs

Oxygen - O - 0 legs

Hydrogen - H - 4 legs

Nitrogen - N - 2 legs

Potassium - K - 4 legs

Phosphorus _ P 1 leg

An element can be rotated, reflected but not stretched in any way, so that the only possible bonds are (here I don't know how to rotate the chars, if somebody can help it would be welcome):

$$CH \;\mathrm{(with\;the\;C\;on\;top\;or\;bottom\;rotated\;by\;90\;degrees)}\\CK \;\mathrm{(with\;the\;C\;on\;top\;or\;bottom\;rotated\;by\;90\;degrees\;or\;to\;the\;right\;rotated\;by\;180)}\\ HK\;\mathrm{(on\;top\;of\;each\;other\;or\;on\;the\;side\;rotating\;one\;by\;180)}\\ NN\;\mathrm{(with\;one\;reflected\;has\;two\;legs\;on\;top\;and\;two\;diconnected\;legs\;on\;bottom)}\\ P\;\mathrm{(with\;anything)}\\ O\;\mathrm{doesn't\;bond}$$

These are the only possible elements passed from STDIN. Notice that the difference between H and K is that K can bond also laterally with a C.

Extra Rule

If no reaction is possible, the output should be equal to the input

Score

1 point per reaction. Bonus: X3 the score if you can print the reaction diagramatically, i.e. print the shape of the molecule (like in the comic)

Example

$$Input \rightarrow Output\\ C\,C \rightarrow (C_2)\\ N \, N \rightarrow N \, N\\ C\,N \, N\,P\,P \rightarrow (C N_2 P_2)\\ C\,C\,K \, H\,H\rightarrow (KC_2H_2)\\ C\,H\,O\rightarrow C\,H\,O $$

Answer 5

Note: I think the question is fine. I just need some more testcases for it.

---

---

You are given the priority order of alleles for a particular trait. For example,

A B
O

means that A and B are equally dominant and O is recessive to both of them. An organism has exactly two alleles, but only the dominant trait(s) is/are expressed. So an organism with gene AO will express only A but an organism with gene AB will express both A and B. An organism with two same alleles will express that allele only.

Each offspring will receive two alleles - one from the mother and the other from the father. So if the initial parents are AB and AO, the offspring formed will be:

AA - 25%
AO - 25%
AB - 25%
BO - 25%

Expressed traits will be

A - 50%
AB - 25%
B - 25%

Offspring of one generation may breed only with a single member of the opposite sex in the same generation during its lifetime. Assume for the sake of this challenge that every male finds a random female in the same generation and has exactly two children - one male and one female. Siblings may interbreed. Note that, except for the first generation, we can ignore the sex of the individuals as their sex chromosomes assort independently of their other characteristics.

Input

• Priority order of all alleles (may include unnecesary alleles)
• Genotype of every organism in initial generation
• Number of generations created
• Any one allele
• (Optional) Number of lines of input for priority order (for languages like C++)

Output

• Probability of the specified allele existing in a randomly selected individual in the specified generation (accurate to three decimal places)

Challenge

• Once two/three answers are posted, I'll use the same testcases in all of them to see which of them are faulty.
• After a week (or I could prolong the deadline) I will upload a lengthy test case in a few days. The code that solves it in the fastest time wins.

Sample data (Some simple testcases)

#1

A
B
C
Male(s) - AA
Female(s) - AB
5
C

Output 0

#2

A
B
C
Male(s) - AA
Female(s) - AB
2
A

Output 0.75

#3

A B
C D
Male(s) - AC,BD
Female(s) - AC,BC
1
C

Output 0.125

Answer 6

Cops and Robbers - Find the Formula

Cops will write a function that takes numerical inputs and produces numerical outputs (note - outputs can be any base and may contain letters). They will post the language, the number of bytes it takes to write the code (up to 128), rounded up to the nearest power of 2, as well as a minimum of 2 test cases. The robbers will try to write a program that takes the same numerical inputs as the test cases and produces identical outputs.

Note - PRNG's, hashing, and other forms of encryption are not allowed.

Scoring

Cops (if safe)

The floor of the product of:

• 128 divided by the power of two rounded up for the bytes
• The natural logarithm of the number of test cases

If cracked, -10 points.

Robbers

The floor of the quotient of

• Half the number rounded up to by the cops
• The natural logarithm of the number of test cases

Answer 7

Quiddler

Quiddler is a card game where you try to create words from letter cards drawn from a deck. A word is defined as being more than 2 cards in length. Sometimes letters are combined on cards in this game, however that will not be the case in this challenge.

Your mission is to write a program which creates words from the letters read in on standard input. Your dictionary of words is the words file on any standard unix system. You may assume that all strings this file is all lowercase.

Input

The string of letters you can use to create words is read in on standard input. This string will be all lowercase, and will not have any spaces in it.

Valid examples are:

actlj
jactl
ljdkj
jjabc

Invalid are:

jklKLJKKJLKUIU
klj kljklj djkas;

Output

The list of all possible results from said string each string. Remember you can produce multiple words in the same answer.

Examples of valid output include. Please remember that I came up with these off the top of my head, and may not be complete. Input is left aligned and the output is presented as the indented lines. The -> is for your benefit.

tacb  -> 
         cat
         act
         bat
         tab

fivquedrr ->
         five qud
         quid five
         river
         quiver

The order of the solutions output does not need to be in any specific order.

The environment

This program must run in a standard UNIX-like environment. This means that you may use any standard shell (bash, ksh, csh, zsh, fish), and you have access to all the standard tools. This challenge is restricted to the shell scripting languages.

The path to the dictionary file in the environment variable, DICT, the path to the file should not be in any valid solution. Use $DICT as the path to the dictionary. This is included so that you can provide testing instructions for your program.

Winner

The winner is the one with the fewest bytes of code that produces the correct output.

Answer 8

Ancient Language Translator

<insert a silly story here>

Task:

Write a program that takes an English sentence and translates it into the Ancient Language. You have to implement at least 42 words. For the purpose of this challenge, you do not have to care about special rules such as "(may be shortened to al when used as a prefix, as in albitr)".

Input:

An English sentence.

Output:

A translated version of the input, simply replace the English words with the Ancient ones.

Examples:

To be added.

Scoring:

Suggestions?

Answer 9

Nested Header List

The goal of this challenge is to complete a list of consecutive nested header numbers when given a start and an end. When given 1.1.1 and 1.1.5 you should generate 1.1.1, 1.1.2, 1.1.3, 1.1.4, 1.1.5

Specific Rules

1. Your entry must take in a start, end, and multiple optional range parameters. Parameters can be taken form STDIN (or nearest equivalent) or a file.
2. Your entry may assume valid input
3. Input will be of the following format:
   1. start and end will be strings of . delimited integers of the same length
   2. start and end will have three segments; (1) set values, (2) iterator, (3) trailing values.
      • The iterator is the first value which differs between start and end.
      • The set values are the values before the iterator. These values never change
      • The trailing values are the values after the iterator. These values iterate up as determined by the range parameter(s). All trailing values will be 1.
   3. range will be a list of integers with a length corresponding to the number of trailing values. When there are no trailing values, range is not specified. The value of range corresponding to each trailing value determines the inclusive upper bound which that entry iterates to.
4. Output will be to STDOUT (or closest alternative) and will show each value separated by at least one delimiter. Delimiter can by any character or string of characters, but it must be consistent. Output must be sorted correctly

Examples

start = '1.1.5.1', end = '1.1.6.1', range = [5]
Output: 1.1.5.1, 1.1.5.2, 1.1.5.3, 1.1.5.4, 1.1.5.5, 1.1.6.1
                                                  ^
                                                  previous value is iterated
                                                  only when iterating value
                                                  limit set by range


start = '1.1.5.1', end = '1.1.7.1', range = [5]
Output: 1.1.5.1, 1.1.5.2, 1.1.5.3, 1.1.5.4, 1.1.5.5, 1.1.6.1,
        1.1.6.1, 1.1.6.2, 1.1.6.3, 1.1.6.4, 1.1.6.5, 1.1.7.1

start = '1.5.1.1', end = '1.6.1.1', range = [5,2]
Output: 1.5.1.1, 1.5.1.2, 1.5.2.1, 1.5.2.2, 1.5.3.1, 1.5.3.2, 
        1.5.4.1, 1.5.4.2, 1.5.5.1, 1.5.5.2, 1.6.1.1

This is code golf so shortest code by bytes wins.

Bonuses

1. Allow trailing values to be values other than 1 in end parameter - 12.5% off
2. Handle incorrect number of values in range parameter - 12.5% off
3. Handle end less than start by producing list in reverse - 50% off

Answer 10

Count the Connect Four Positions

fastest-code

Connect Four is a two-player game on a rectangular board. The board is m spaces wide and n spaces tall, and players alternate placing pieces in columns. A placed piece always fills the lowest empty space in a column, and a player may not move in a full column. In the standard game, m=7 and n=6.

The game ends when one player completes a row of four pieces vertically, horizontally, or diagonally, or all m columns are full. The edges of the board do not wrap.

Challenge

Write a program or function to determine the number of distinct, legal m by n Connect Four boards after p plies. (A ply is one move by one player.) A legal position is one reachable from the empty board through a sequence of moves in which no player had already won. (A position in which one player has just won is legal.)

Rules

You may assume that 0<=p<=m*n, m<=8 and n<=8.

As usual, hardcoding is not allowed.

Your code should be at most 1024 bytes in length, and use at most 16 GB of memory.

Related: Determine winner of Connect 4

Test cases

[need to add; include OEIS]

Relevant links:

• This Math SE question

• This offsite page

• OEIS sequence for n=7, m=6

Answer 11

Compile from Brainfuck

code-golf

The professors at Brainfuck University realized their jobs are horrible, because all they do is discuss quantum mechanics using Brainfuck, so they decided to take their programs and compile them to a better language. Because of the randomness of quantum particles, their program needs to be small so it has a smaller chance of being disrupted in the Higgs Field.

Your task is to get a Brainfuck program from any input and output that program transcompiled into another language. Here is an example:

++-->><<

Compiles to the C program:

#include <stdio.h>
#include <stdlib.h>

int main(int argc, char **argv) {
    unsigned char *cell = calloc(30000, 1);
    unsigned char *cells = cell;
    if (!cell) {
        fprintf(stderr, "Error allocating memory.\n");
        return 1;
    }
        //actual program
        ++*cell;
        ++*cell;
        --*cell;
        --*cell;
        --cell;
        --cell;
        ++cell;
        ++cell;

        free(cells);
        return 0;
}

Score

Your score is the size of your program added to the size of the output.

Bonuses

• If you support Brainfuck-ng, subtract 30

Answer 12

Logic Puzzle Solver/Inference Engine

Your goal is to take the clues and other facts given in a grade-school logic grid puzzle such as these and solve the puzzle. To keep things simple, your program will only solve specific logic problems about which it can make the assumptions you wish to hard-code in, but the program need not perform any checks to see if those assumptions can be made.

You may not use:

• A declarative language
• Any function provided - by an external dependency - for the solving of a logic puzzle.

Input

Your program will take input from the command line. After gathering assumptions, the program will ask for facts written as such:

subject.verb object

for all true facts. For false facts:

!subject.verb object

Examples: If Chad bought donuts,

Chad.bought donuts

If he didn't:

!Chad.bought donuts.

If Nancy's last name isn't Wesley,

!Nancy.is Wesley.

Output

Your program will output its conclusions as such:

subject verb object.

So, if your program determines that Chad bought donuts and Nancy's last name is Wesley, then it will output:

Chad bought donuts.

Nancy's last name is Wesley.

Answer 13

New user to Programming Puzzles!

Spades CHALLENGE!!!

I would like a king of the hill challenge for bots playing the game of spades. Spades is a card game. The rules are shown on wikipedia.

Scoring rules:

• Nils allowed, with 50 points for completion (not 100). -50 for losing.
• 10 points a hand, with sandbagging allowed.
• Partnership Playing
• Sum of all four players hands cannot equal 13!

Winner is first to 500 points. The bot will be paired with all other bots entered into the competition. The pair of winners will be crowned with +10 meta-points (Mpoints), losers will get -1 Mpoints. Whoever has the most Mpoints wins - ties based upon sum of points earned in the games.

Gameplay:

• The bot with the lowest Mpoints bids first. Bidding proceeds from down until reaching 4th slot, then goes back to first slot and continues. Play starts with this player.
• The bot will be given a string of cards - AS for Ace of Spades, JC for Jack of Clubs, 2D for 2 of Diamonds, 8H for 8 of hearts, randomly dealt from a single 52-card deck. Each will be comma separated: AS,JC,2D,8H,4C,5S,8D,3D,3S,JS,10S
• The bot will get the bids from the other bots before making the bid.
• Upon winning a hand, the bot gets to continue making plays until someone else wins the hand.
• Hands are scored at the end using the scoring rules. If a team's score is less than 500, gameplay continues with a new hand.

Unfortunately, I do not know how to setup the servers or any of that stuff. I just think the challenge will be interesting. If anyone can help with that, run with it. I like to watch these challenges unfold - but I'm too much of an engineer and not enough of a programmer to make these kinds of programming happen.

Answer 14

I was thinking about a challenge on wrapping time.

I am a member here for 34 days now. I would have expected for the date to wrap to 1 month.

Rules:

• starting with hours from the joining date to now.

• first wrapping happens when you go over 24 hours, the count will be in days now.

• second wrapping happens after reaching 30 or 31 days, you can decide, to months.

• third wrapping really wraps when a year is reached, it shall be displayed as i.e. 2 years 3 month.

• round to neares full unit, i.e. 43 days = 1 month, 50 days = 2 month

• take either a build in function to get the current time or hardcode it to ´2015-12-19-11´ <- time when challenge will be posted. If hardcoding it is shorter you may take the bytecount from the hardcoded version.

• Dates after the current or hardcoded date can do whatever.

Input

The joining date and hour like ´YYYY-MM-DD-HH´ the delimeter does not have to be a - choose whatever you like.

Output

The time according to the rules above.

Example:

In: 2015-12-10
Out: 9 Days

In: 2015-10-28
Out: 2 Month

Answer 15

Browser identifier

code-golfjavascript

There are three major browsers at the moment, Internet Explorer, Google Chrome and Firefox. Sometimes, the JavaScript engines inside of these browsers work a bit differently, and that can break some applications. Therefore, we need a way to identify what browser the user is currently using!

Your answer should be a JavaScript program or function, that when run on the latest version of a browser, should output a string representing that browser. The string outputed could be anything, as long as it stays the same every time you run it. Output should go to a HTML paragraph with id O, console.log, or as return value.

Please put your answer in a snippet, along with <p id="o"></p> in the HTML section if your answer uses it.

(scoreboard snippet goes here)

Answer 16

Parse a tree for pruning

code-golf ascii-art

Windows supplies users with tree: a neat little tool that converts a directory tree to ASCII-CP437 art. It's a very human-readable format. However, it's a bit useless if you want the directory tree of an entire drive, or even just the Windows folder, as it's very hard to prune the parts you don't want. Hence this challenge.

Task

Your task is to produce a function or program that will convert the tree from one or both of the input formats into one or more of the output formats. The smaller your code, the more of a head start you have.

Input

There are two types of input that you might be given:

CP437

This is the default.

Folder PATH listing for volume Main Drive
Volume serial number is 00F3-F586
C:\WINDOWS
│   explorer.exe
│   notepad.exe
│   virus.dll
│   WLXPGSS.SCR
│   write.exe
│   
├───Boot
│   │   BootDebuggerFiles.ini
│   │   
│   ├───DVD
│   │       your.txt
│   │       
│   ├───EFI
│   │       pc.txt
│   │       
│   ├───Fonts
│   │       has.txt
│   │       
│   ├───PCAT
│   │       been.txt
│   │       
│   └───Resources
│           wrecked.txt
│           
├───System
└───System32
        cmd.exe
        conhost.exe
        winlogon.cmd
        winlogon.exe

ASCII

This will be easier to parse for many languages.

Folder PATH listing for volume Main Drive
Volume serial number is 00F3-F586
C:\WINDOWS
|   explorer.exe
|   notepad.exe
|   virus.dll
|   WLXPGSS.SCR
|   write.exe
|   
+---Boot
|   |   BootDebuggerFiles.ini
|   |   
|   +---DVD
|   |       your.txt
|   |       
|   +---EFI
|   |       pc.txt
|   |       
|   +---Fonts
|   |       has.txt
|   |       
|   +---PCAT
|   |       been.txt
|   |       
|   \---Resources
|           wrecked.txt
|           
+---System
\---System32
        cmd.exe
        conhost.exe
        winlogon.cmd
        winlogon.exe

Output

There are several possible types of output you can return, each suited to a different type of language.

Array / List hierarchy of strings

The first element of each array / list is the name, the rest are the contents. Files should be represented by strings, empty folders should be represented by a single-length array containing one string. Note: This should be returned from a function as an array / list, not printed as a string.

["C:\WINDOWS", "explorer.exe", "notepad.exe", "virus.dll", "WLXPGSS.SCR", "write.exe", ["Boot", "BootDebuggerFiles.ini", ["DVD", "your.txt"], ["EFI", "pc.txt"], ["Fonts", "has.txt"], ["PCAT", "been.txt"], ["Resources", "wrecked.txt"]], ["System"], ["System32", "cmd.exe", "conhost.exe", "winlogon.cmd", "winlogon.exe"]]

Object / Dictionary

Similar to array / list, but a little more intuitive. Folders should have the value of their contents as another object / dictionary. Files should have the value "FILE".

{"C:\WINDOWS":{"explorer.exe":"FILE","notepad.exe":"FILE","virus.dll":"FILE","WLXPGSS.SCR":"FILE","write.exe":"FILE","Boot":{"BootDebuggerFiles.ini":"FILE","DVD":{"your.txt":"FILE"},"EFI":{"pc.txt":"FILE"},"Fonts":{"has.txt":"FILE"} [...] } [...] } [...] }

Lisp-style string

Similar to array / list, where the head of the list is the directory name and the tail is the contents. An empty directory is a list with no tail, and a file is a string.

No WAY am I putting an example. No way. I've spent half the time on this question creating the examples. No way. Ok, maybe later.

Bonus

If you satisfy none of these bonuses, your submission is still valid. But its score shall infinite, so it is non-competitive.
These bonuses are to multiply your score by. Bonuses stack by multiplication. These bonuses must all be achieved consistently to be awarded.

• 100% Allow at least one input mode and output mode
• 50% Allow both input modes
• 90% Output in exactly two ways
• 50% Output in one of two ways depending on parameters
• 80% Output in exactly three ways
• 25% Output in one of three ways depending on parameters

Answer 17

Identifying spies in "Resistance"

This is still very rough, but I think it has the makings of an interesting challenge. Please help me improve it. What do I need to add? What do I need clarify?

Resistance is a party game that pits "resistance members" against "imperial spies" on a series of missions. A very important aspect of the game is that the resistance members do not know who the spies are, whereas the spies do know who is who.

How the game works

The relevant details of the game will be added here. For now, just check the Wikipedia page linked in the title.

Challenge

your challenge is to write a program that takes as input the details of every round and outputs who it thinks is a spy after each round. There are 5 rounds (missions) in a game of resistance, so the program/function will take in all the data for the first round, which includes

1. Each proposed team to go on the mission
2. Each public vote following each proposal
3. The final team to go on the mission
4. The outcome of the mission (i.e. how many passes and how many fails)

It will then output who it thinks is a spy. It will then do the same for each subsequent round.

Important Details

We will be playing resistance for (6?) people, A, B, C, D, E, and F.

Input format is flexible. It may be done round by round or all at once. However, since ach submission is outputting something for each of the five rounds, the submission may not use information from future rounds (if all information is given at once) in judging the current round.

Here is an example of possible input format:

Since the first mission requires two people, and person A is the first mission planner, the only thing input would be two letters in {A,B,C,D,E,F} indicating his selection. Then the votes of each person, in order, would be input. This continues until a mission team is accepted. Then the votes given on the mission would be input, in no/any particular order. The program would then output the letters of the two people it thinks are spies (there are 2 spies in a 6 person game). Here is an example

A B              # A selects A and B for first mission
P P P F F F      # Everyone votes, mission team is not accepted (lacks majority pass)
B F              # B selects B and F for first mission
P P P P P F      # Mission team is accepted (majority pass)
P F              # Mission fails (there is at least one fail vote). Note that the order does not matter here. 

The bot would then output two people, the people it thinks are most likely to be the spies based on all the information it has up to this point.

B F              # Any two person subset is acceptable

Input then continues for the next 4 rounds, until the game is over.

Scoring

I will write several hundred test cases (from actual games played online). Then each output will be scored in the following way:

• 1 point for each correctly guessed spy.
• 1 point for guessing both spies correctly.

The submission's total score will be the sum of all scores on all rounds in all games. The program will never be told who is a spy (unless it is used to self-score and does not factor into the actual guessing) but this information will be available with the test cases for scoring purposes.

Tie break is code golf.

---

Meta: I think I'm going to remove output after the first round, because very rarely do people ever fail the first mission. So it will likely just be pure chance.

Answer 18

Nth Regex

This challenge('s explanation) is simple: given a number n and a regex r, output the nth string that matches r!

The regex r uses the syntax used in Python, described here. The regex will be for the whole string, meaning the regex will be implicitly wrapped in ^$.

The only valid strings are printable ASCII characters, and they count up like base 95 (ASCII codes 32-126).

To prevent people from brute-forcing it, I was thinking of making it fastest-code.

Answer 19

Robots on ice

Part 1 - The basic

You are helping a robot R on an iced island. R can go up/down/left/right. But since the island is made of ice, it cannot move only 1 square at a time, but instead moves in straight line. Your task is to help R reach G.

Input

The input (file, stdin, input, whatever suits you) is an n×m matrice with the following characters:

• R The robot
• G The goal
• # An obstacle that stops the robot
• Ice

The island is surrounded by a wall: the edges of the matrice always consist of #.

Output

A list of instructions consisting of U/D/L/R, corresponding to up/down/left/right.

The list should be the shortest possible. The distance traveled by the robot doesn't count.

The output should be the map with the instructions on it, with each instruction at the right coordinates. Each of RG# should be displayed if not overriden by an instruction (that will always be the case for R)

Example

Input:

##########
# #      #
#        #
#  G #   #
#        #
#    R#  #
#        #
##########

Output: Since D,R,U,L,D is one possible solution, the output should be:

##########
# #D    L#
#        #
#  G #   #
#        #
#    D#  #
#    R  U#
##########

Another solution, U,R,U,L,D, should be output as:

##########
# #D    L#
#        #
#  G #   #
#    R  U#
#    U#  #
#        #
##########

Input:

####################
###R             ###
#  ######          #
#      #####       #
##                G#
###              ###
####################

Output:

####################
###R            D###
#RD######          #
#U L   #####       #
##R               G#
###U            L###
####################

You can assume that the puzzle always has at least 1 solution

Part 2 - New options

The pitch is the same, but new characters can be displayed:

Input

The input (file, stdin, input, whatever suits you) is an n×m matrice with the following characters:

• R The robot
• G The goal
• # An obstacle that stops the robot
• Ice
• W Some water. Robot doesn’t like water
• B a Box. Robot can push the box 1 square at a time, in front of him (not on the side), if the next square is . It cannot be pushed into the water, through the goal… Robot cannot push 2 boxes at once. When pushing, the robot stays in place.
• 1 a numbered teleportation door. Always in pair. When entering a teleportation door, Robot will continue sliding in the same direction through the other door. Can be used more than 1 time.

The island will this time be surrounded by water.

Output

A list of instructions consisting of U/D/L/R, corresponding to up/down/left/right.

The list should be the shortest possible. The distance traveled by the robot doesn't count.

This time the output won't be displayed on the map, but on stdout. The format doesn't matter:

UDRL

or

U
D
R
L

are accepted

Example

Input:

WWWWWWWWWW
W W      W
W        W
W  G 1   W
W        W
W    1R  W
W        W
WWWWWWWWWW

Output:

L

Input:

WWWWWWWWWW
W W      W
W    #   W
W  G     W
W        W
W    BR  W
W        W
WWWWWWWWWW

Output:

LLUL

The first L moves the box (but not the Robot) 1 square:

WWWWWWWWWW
W W      W
W    #   W
W  G     W
W        W
W   B R  W
W        W
WWWWWWWWWW

Input:

WWWWWWWWWWWWW
W         # W
W G 2       W
W           W
W   B 1     W
W#2         W
W   # 1R   #W
W          #W
W    #     #W
WWWWWWWWWWWWW

Output:

L #entering teleportation 1
L #pushing the box to the left
L #going to the box
U #entering teleportation 2

The solution RULU is also valid

Input:

WWWWWWWWWWWWW
W #         W
W     #     W
W#   1      W
W           W
W           W
W    1 R    W
W           W
W    G      W
WWWWWWWWWWWWW

Output:

L #entering teleportation 1
U #going to the wall
R #going to the wall
D #entering teleportation 1

In this situations, Robot cannot moves to the left:

W  GBR   W

W  #BR   W

W  BBR   W

W  WBR   W

W    R   W

You can assume that the puzzle always has at least 1 solution

Part 3 - With help

Same as part 2 but with others robots:

Input

The input (file, stdin, input, whatever suits you) is an n×m matrice with the following characters:

• R The robot
• G The goal
• # An obstacle that stops the robot
• Ice
• W Some water. Robot doesn’t like water
• B a Box. Robot can push the box 1 square at a time, in front of him (not on the side), if the next square is . It cannot be pushed into the water, through the goal… Robot cannot push 2 boxes at once. When pushing, the robot stays in place.
• 1 a numbered teleportation door. Always in pair. When entering a teleportation door, Robot will continue sliding in the same direction through the other door. Can be used more than 1 time.
• abcde up to 5 robots that can move the same as Robot. They cannot go through other robots, including R, and can pass through the Goal. They can be sacrified by going into the water. They can be used more than 1 time.

The island is surrounded by water.

Output

A list of instructions consisting of U/D/L/R, corresponding to up/down/left/right, prefixed by the name of the robot moving.

The list should be the shortest possible. The distance traveled by the robot doesn't count.

As usual, theformat doesn't matter:

a:UDR
R:LU

or

aU
aD
aR
RL
RU

are accepted

Example

Input:

WWWWWWWWWWWWWWWWWW
W        a     # W
W   G            W
W                W
W                W
W                W
W             R  W
W                W
W       #        W
W             #  W
W                W
WWWWWWWWWWWWWWWWWW

Output:

a:R
R:UL

The answer DLUL is valid but not the shortest

Input:

WWWWWWWWWWWWWWWWWW
W                W
W                W
W                W
W                W
W  G    a    R   W
W                W
W                W
W                W
W                W
W                W
WWWWWWWWWWWWWWWWWW

Output:

a:U
R:L

Input:

WWWWWWWWWWWWWWWWWW
W           #    W
W                W
W  #             W
W           G    W
W                W
W                W
W           b    W
W   R       a    W
W                W
W                W
WWWWWWWWWWWWWWWWWW

Output:

b:U
a:UL
R:UR

Input:

WWWWWWWWWWWWWWWWWW
W                W
W           #    W
W          B     W
W  #             W
W     G          W
W                W
W  #             W
W   e       R#   W
W                W
W           a    W
WWWWWWWWWWWWWWWWWW

Output:

e:R
R:U
a:UL
R:LLDLUR

Input:

WWWWWWWWWWWWWWWWWW
W                W
W         G #    W
W   b            W
W                W
W           a    W
W   c            W
W           #    W
W   R            W
W                W
W          #     W
WWWWWWWWWWWWWWWWWW

Output:

a:U
b:RD
a:D
C:RD
R:RU

Input:

WWWWWWWWWW
W    G   W
W aBbBR  W
WWWWWWWWWW

Output:

a:L
b:LL
R:LLU

In this situations, Robot and b cannot move to the left:

W  GaRb  W

W  #b#R  W

W aBbBR  W

You can assume that the puzzle always has at least 1 solution

Sandbox Questions

Has it been done before?

What do you think? Is it understandable? Should I do 3 separated challenges (and in the sandbox)? More, less? Which part needs more examples? What part is unclear?

I would like to go with shortest-code win. Should I use kolmogorov instead?

Answer 20

Everything about PI

code-golf

Pi is the most popular transcedental number. As a result, pi has been thoroughly studied. This challenge is in spirit of 9-Hole challenge.

1. Digits of PI

Given n and k, output n'th digit after the decimal point in the base-k representation. For example, the 5th digit of PI base 10 is 9.

5 10
9
10 2
0
6 16
10

If the base is more than 10, output like in the last test case

More information : http://www.virtuescience.com/pi-in-other-bases.html

2. Continued fraction of PI

Given n, output n'th number in continued fraction of Pi.

5
292
7
1

3. Closest to PI

Given a positive integer d, output the integer n such that n/d is closest to pi. For example, 17/5 is closer to pi than any other n/5.

 5
 17
 7
 22
 21
 66

4. Closest to PI 2

Given a positive integer n, output the integer d such that n/d is closest to pi.

5
2
7
2
20
6

Restriction.

1. You should not have any floating-number buildin, only integer, including PI constants.
2. Standard loophole is disallowed.
3. The program may be 4 program or a program that reads challenge number.

Sandbox Question

Originally, I have 5 challenge, 4 more required. Now, one of them is dupe. 5 more required.

Answer 21

How to print 2016 using only the number 2?

Print 2016 using only the digit 2 operators and native language built-in functions.

The objective is to

• Output the integer 2016 without using any digits except 2.
• no characters / strings literals are allowed, i.e. no tricks like ord('b')
• The code that uses the least number of 2s in the code wins.

For example, in python, the following code uses 8 twos.:

>>> int(str(2**2*2) + str(2**2)) * int(str(2) + str(2**2))
2016

Or like this code, uses 13 twos:

>>> 2 ** 2 ** 2 * 2 ** 2 ** 2 * 2 * 2 * 2 - 2 ** 2 ** 2 * 2
2016

Answer 22

Growing Quine 2

code-golfquine

Your task is to give program P1..P5 so that.

1. For all k<5, length of Pk < length of Pk+1
2. For all k<5, Pk outputs Pk+1
3. For all k<=5, Pk is semi-pristine program. (Program that if any run on the source-code is deleted, will output different output)
4. P5 return P1 sufficient times that the output will be longer than P5

Shortest P1 wins

Answer 23

Zipping double quine.

code-golf quine

You must provide 2 program, A and B. Both are a quine and have same length.

If A and B is zipped each other(Both when A is zipped first, or B is zipped first), the result is also an quine.

Standard Loopholes is not allowed and standard quine rules apply.

Examples

If program A is ABCDEF and program B is GHIJKL then

slangi "ABCDEF"
ABCDEF
slangi "GHIJKL"
GHIJKL
slangi "AGBHCIDJEKFL"
AGBHCIDJEKFL
slangi "GAHBICJDKELF"
GAHBICJDKELF

Answer 24

War of Flatland

king-of-the-hill

If you haven't read Flatland, please do so here. It is a must-read, for mathematical and non-mathematical alike.

Oh no. No no no! War has broken out in Flatland. Society has crumbled, and all the women and children are either hiding or dead¹. It is total anarchy, kill or be killed. It is such conflict that the 4th dimensional people have erected indestructible borders to prevent the conflict spreading.

On the plus side, if you came out on top, you could rule (some of) the entire world!

Specifications

• You can be a shape with three or more sides. (No women¹, remember?)
• All shapes are regular.
• You can only see by sight. (No feeling; you'll be killed if you get close enough to do that!)
• Everybody starts with 1 health.
• You can hurt other people by stabbing one of their edges with a vertex.
• The vertex of an n sided shape deals 1/n damage.
• An n sided shape has 4n angles of vision (sensors evenly spaced around the shape which see the nearest point and return the distance to it).
• An n sided shape can see 2n different distances (range [0,16))
• People don't see themselves. (What good is sight if your body gets in the way?)
• People are all the same size (radius).
• People can see everything within 16 units of their centre point.
• If your health is 0 or below, you are killed.
• The world has borders.
• You can rotate by a maximum of 15 degrees either direction, then move exactly 1 unit towards either of your vertices every turn.
• Each shape's "radius" is 8 units.
• Degrees are anticlockwise from 3 O'clock. The 0th sensor is at 3 O'clock relative to the shape's orientation.

¹ This is not me being sexist. Read Flatland.

Sandbox Meta:

I am using the Sandbox as a public incubator. I will build up and work on the challenge until it is ready, then post it as a question. But it made more sense to let others see, comment on and help with this challenge's development.

The Specifications are probably not going to remain in this format once the Stack Snippet and actual code is up and running.
I am working on, and have got quite far with, a JavaScript class to let people write code. If anyone can write a code to do the _^boring rendering thing onto a HTML5 canvas, I would be grateful.

Stuff I plan to add:

• A stack-snippet battlefield
• A JavaScript class to let people write code
• A web-socket system to let people make submissions in other languages
• A system to pull submissions from answers (I'm no good at this sort of thing)

Answer 25

Print Euler's number on its own graph

code-golf

Print the first n characters of Euler's number (e, 2.718281828459...) on a 'graph' of e^n. For example, input 3 (the x and y-axis scales here are provided for reference, and need not be implemented in your program):

20 |         1
19 |
18 |
17 |
16 |
15 |
14 |
13 |
12 |
11 |
10 |
 9 |
 8 |
 7 |     7
 6 |
 5 |
 4 |
 3 | 2
 2 |
 1 |
 0 | - - - - - - -
     1   2   3
      digit #

In the example above, note that:

• Three digits of Euler's number are presented
• Each digit is shown at a height equal to e^n, where n is the digit number. 2, for example, is shown at height 3 because e^1 = 2.72, which we round up to 3. You may round up or down, see below.

Various other informational bits:

• Rounding need not be implemented; 271 is acceptable output for input 3, as is 272.
• You will always be provided with input >= 1 , and your input will never contain decimal places nor any characters other than 0-9.
• You may round the y value up or down, I.e. e^3 = 20.0855 may be shown as y=20 or y=21.
• Your graph must have higher y-values at the top and higher x-values to the right; it must have a positive slope
• You may use any amount of horizontal spacing >= 1 between successive digits. In the example above, there are 3 spaces between successive digits. You just can't have digits stacked on top of eachother.
• You are not required to print scales on the x or y axis.
• Your input will always be <= 10.
• You may hardcode the required digits if you so desire.

Answer 26

Print as many numbers as you can

A restricted-code challenge where you have two occurrences of each ASCII character from 20 to 7E to write as many programs as you can to print single distinct integers (one integer per program). For example, you cannot have A and AA to print 10 and 1010 in CJam, respectively, as that is three occurrences of A.

Full programs are not required.

You get 1 point for each integer you print. In the case that two answers create the same number of integers, the tiebreaker is the answer that uses the fewest bytes to create the integers.

Is this a good idea for a challenge? Also, is it a dupe? I feel like I've seen it before but I'm not sure.

Answer 27

Find my way

I wanted to propose a challenge that is code golf (shortest answer wins), but with more programming challenge than parsing and printing funky text. Let's see if it sticks.

You are given a maze map, such as this:

#################################################
##########                    ######  ##### 1 ###
####   ##   ######  ########  #####     ####  ###
##   ###   #######  ########   ######  ###    ###
## X  ##  ########  #####      ####   #####  ##  
#                      ##      ##    ##      ##  
###################   ####   #####   #   ##  ##  
###   #############  #####   ######  #  ##   ####
##   ###             ##      ##    ##   ##     ##
#   ##      ####     ##  #   #   #      ###    ##
#  ####              ##      #   #  #        ####
#   #####   ###    ####   #####  #  #############    
#  #####   #####  ####   ##  ##     #############
   ###             ##     #  #     ########      
   ##     ####    #####   ####     ########   ###
  ##     ###                ##        #####   ###
          #####################   #   #####      
#####       ##############  ##   ###    #########
##      #   ###     ######  ##    #   ###########
#########        #               ##########      
      ###   ###     ##   ##################      
      ###   ##########   ########################
#################################################

and you need to help the player 1 find the goal X. You can assume the following rules apply to the input map:

• it is a n x m ASCII rectangle (i.e. n lines of m characters);
• only the following characters are allowed: #, 1, X, (whitespace) and newline;
• # represent walls (that can't be crossed), represent empty space (that can be crossed); you can go anywhere in the n x m rectangle but you can't leave it (it's not Pacman).

If the maze has a solution, you shall produce an output of the following form:

#################################################
##########DLLLLLLLLL          ######  ##### D ###
####   ## D ###### U########  #####     ####D ###
##   ### DL####### U########   ######  ###  D ###
## X  ## D######## U#####      ####   ##### D##  
#  ULLLLLL         UL  ##      ##    ##     D##  
################### U ####   #####   #   ## D##  
###   ############# U#####   ######  #  ##  D####
##   ###  RRRRRRRRRRU##      ##    ##   ##  D  ##
#   ##    U ####     ##  #   #   #DLLLL ### D  ##
#  ####   U          ##      #   #D # ULLLLLL####
#   ##### U ###    ####   #####  #D #############    
#  #####RRU#####  ####   ##  ##  DL #############
   ###  U          ##     #  #  DL ########      
   ##   U ####    #####   ####DLL  ########   ###
  ##RRRRU###                ##RRD     #####   ###
    ULLLLL##################### D #   #####      
#####    U  ##############  ##  D###    #########
##      #U  ### DLL ######  ##DLL #   ###########
#########ULLLLLLL#ULLLLLLLLLLLL  ##########      
      ###   ###     ##   ##################      
      ###   ##########   ########################
#################################################

where:

• the letters U, R, D and L represent movements by 1 character to the, respectively, up, right, down and left;
• the letter chain represent a valid path from the original 1 (which has been replaced by a direction character) and X.

If the maze has no solution, you should return void, NULL or anything equivalent.

Final rules:

• this is code golf, so the shortest solution wins;
• typical code-golf rules for input and output apply.

Answer 28

Iterating through Doubles

This challenge is relatively simple: You are passed two floating point numbers, a and b; you must print every floating point in between in order.

• I don't care if your output includes a or b. You can choose to include/exclude them if you wish. For my examples, I will include a, but exclude b.
• You can assume that a <= b
• You should use IEEE 754 floating point numbers. As to the format of the numbers, I do not care, though I will be using binary32 in my examples.
• Your program must not print any NaNs, infinities, or print out the same number twice. -0 is the same as 0.
• Ifa or b cannot be perfectly represented in floating point, you must round-to-nearest them (standard for most languages). You can assume that a and b won't round to infinity.
• Your program must have a runtime of O(N), where N is the total number of floating point numbers in between a and b.
• Your program must not use more than O(1) storage. The only exception to this is for storing your output before printing it all.
• Builtins that are able to generate floats in order are not allowed (such as Julia's nextfloat())

For the following examples, I have used this webpage to generate the numbers, and thus my examples may have human errors.

-5.6E-45, 5.6E-45
-5.6E-45, -4.2E-45, -2.8E-45, -1.4E-45, 0, 1.4E-45, 2.8E-45, 4.2E-45

-0, 0
No output, though printing either 0 or -0 would be allowed (but not both)

299.9998, 300.0002
299.9998, 299.99982, 299.99985, 299.99988, 299.9999, 299.99994, 299.99997, 300, 300.00003, 300.00006, 300.0001, 300.00012, 300.00015, 300.00018, 300.0002

1.9999998, 2.000001
1.9999998, 1.9999999, 2, 2.0000002, 2.0000005, 2.0000007, 2.000001

-3.4028235E38, -3.402822E38
-3.4028235E38, -3.4028233E38, -3.402823E38, -3.402829E38, -3.4028227E38, -3.4028225E38, -3.4028222E38

3.4028229E38, 3.4028235E38
3.4028229E38, 3.402823E38, 3.4028233E38, 3.4028235E38

Answer 29

Coaxial and Copolar?

code-challengegeometrytrigonometry

Introduction

SANDBOX NOTE: Diagrams soon

Copolar: Two triangles ABC and A'B'C' (not necessarily in the same plane) are said to be copolar if and only if the lines AA', BB', and CC' are concurrent at one point V.

Coaxial: Supoose two triangles ABC and A'B'C' are defined such that AB and A'B' intersect at X, AC and A'C' intersect at Y, and BC and B'C' intersect at Z. Then, the two triangles ABC and A'B'C' are said to be Coaxial if and only if X, Y, and Z are collinear.

Desargue's Theorem: Copolar triangles are coaxial, and conversely.

The Challenge

Your challenge is to write two entire programs (but not necessarily in the same language, if you so desire) which detect whether or not two triangles are Coaxial/Copolar. One program must detect the existence of V, and the other must check the collinearity of X, Y, and Z (As defined above). You should provide some explanation or proof that your two programs perform these two different checks. Your score in this challenge is the Levenshtein distance between the two programs, with lowest score being dubbed winner.

Input

You will receive 6 vectors, all of which containing an x, y, and z floating-point Cartesian coordinate, to represent the vertices of ABC and A'B'C'. This information may be received by your program in any convenient format, including command line arguments, nested lists, etc. The two programs you submit should take input in the same manner.

Output

Your program should print a truthy value if ABC and A'B'C' are coaxial/copolar, and a falsey value otherwise. As this will likely require floating-point calculations, we establish some leniency:

Choose a constant value 0 < ERR < 0.01, for use in both programs.

• If the pairwise intersections of AA', BB', and CC' intersect within ERR units of one another, the given triangles should be considered copolar.

• If the point Z lies closer than ERR distance from the line XY, the given triangles should be considered coaxial.

Standard techniques for checking floating point calculation equality should be sufficiently accurate for this challenge.

Since copolar triangles are also coaxial, the programs should output the same value in all but extreme cases.

It should be assumed that any cross section of the cartesian space provided is an Extended Euclidean Plane. Note that it is possible that the vertex V or any of X, Y, and Z may be an ideal point, and this is a case that should be prepared for.

Test cases

SANDBOX NOTE: Coming soon...

Answer 30

Cookies are being served! Sibling rivalry ensues! Each of the twins wants the maximum quantity of cookie. The problem is that the cookies are of somewhat different sizes, not surprising since they are home baked. So you weigh each of the cookies and devise a program to help you allocate them to each twin such that the difference in total weight of the cookies each twin gets is minimized. Coding up the program is your task today!

Input

Each case is described on a single line that begins with the number of cookies (no more than 100) followed by the weight of each (in integer grams, no more than 1000 grams).

Output

For each case, display the minimum total weight difference.

Sample Input

5 6 8 5 2 6

2 25 62

Sample Output

1

37

---

I asked this earlier and it was put on hold. Not sure what needs to be changed.