## My daughter's alphabet

66

12

The other day we were writing sentences with my daughter with a fridge magnet letter. While we were able to make some(I love cat), we didn't have enough letters to make the others (I love you too) due to an insufficient amount of letters o (4)

I then found out that while one set included 3 e letters it had only 2 o letters. Probably inspired by http://en.wikipedia.org/wiki/Letter_frequency this would still not reflect the actual situation "on the fridge".

## Problem

Given the text file where each line contains a "sample sentence" one would want to write on the fridge, propose an alphabet set with minimum amount of letters but still sufficient to write each sentence individually.

Note: ignore cases, all magnet letters are capitals anyway.

## Input

The file contain newline separated sentences:

hello
i love cat
i love dog
i love mommy


## Output

Provide back sorted list of letters, where each letter appears only as many times to be sufficient to write any sentence:

acdddeghillmmmoostvyy


(thanks, isaacg!)

## Winner

Shortest implementation (code)

### UPDATED: Testing

I have created an extra test and tried with various answers here:

https://gist.github.com/romaninsh/11159751

May we assume all uppercase input? Does the output have to be sorted? – Titus – 2018-12-14T08:56:21.683

2There should be a letter v in the output ;) – Antonio Ragagnin – 2014-04-10T06:35:59.533

1I believe the correct output is: acdddeghillmmmoostvyy – isaacg – 2014-04-10T06:49:55.230

1Damnit, I accidentally bought one pack with lowercase letters too... – PlasmaHH – 2014-04-10T08:41:25.530

40Are we allowed / required to substitute an upside-down M for a W, or a sideways N for a Z? ;-) – Ilmari Karonen – 2014-04-10T11:42:35.080

4Basically you can construct any letter using Is. – swish – 2014-04-10T11:53:49.353

7More seriously, when you say "ignore cases", do you mean that we can assume that the input is already all in the same case, or that we must convert it all into the same case? Also, is it OK for the output to include some leading spaces? – Ilmari Karonen – 2014-04-10T12:01:58.920

2@swish Try making a G out of Is :P Or an S – Doorknob – 2014-04-10T13:09:34.940

3@Doorknob: _\¯ – Ilmari Karonen – 2014-04-10T13:37:56.047

@IlmariKaronen looks more like a backwards Z – Tim Seguine – 2014-04-11T15:33:37.527

@swish or you can use m's as pixels, as they're the closest thing to a filled in square – Cruncher – 2014-04-11T15:56:14.490

Lordy you guys want to bring back 1337 5p33|< ? – Carl Witthoft – 2014-04-12T12:54:28.753

18

# GolfScript, 28 / 34 chars

n/:a{|}*{a{.[2$]--}%*$-1=}%$ The 28-character program above assumes that all the input letters are in the same case. If this is not necessarily so, we can force them into upper case by prepending {95&}% to the code, for a total of 34 chars: {95&}%n/:a{|}*{a{.[2$]--}%*$-1=}%$


Notes:

• For correct operation, the input must include at least one newline. This will be true for normal text files with newlines at the end of each line, but might not be true if the input consists of just one line with no trailing newline. This could be fixed at the cost of two extra chars, by prepending n+ to the code.

• The uppercasing used in the 34-character version is really crude — it maps lowercase ASCII letters to their uppercase equivalents (and spaces to NULs), but makes a complete mess of numbers and most punctuation. I'm assuming that the input will not include any such characters.

• The 28-character version treats all input characters (except newlines and NULs) equally. In particular, if the input contains any spaces, some will also appear in the output; conveniently, they will sort before any other printable ASCII characters. The 34-character version, however, does ignore spaces (because it turns out I can do that without it costing me any extra chars).

Explanation:

• The optional {95&}% prefix uppercases the input by zeroing out the sixth bit of the ASCII code of each input byte (95 = 64 + 31 = 10111112). This maps lowercase ASCII letters to uppercase, spaces to null bytes, and leaves newlines unchanged.

• n/ splits the input at newlines, and :a assigns the resulting array into the variable a. Then {|}* computes the set union of the strings in the array, which (assuming that the array has at least two elements) yields a string containing all the unique (non-newline) characters in the input.

• The following { }% loop then iterates over each of these unique characters. Inside the loop body, the inner loop a{.[2$]--}% iterates over the strings in the array a, removing from each string all characters not equal to the one the outer loop is iterating over. The inner loop leaves the ASCII code of the current character on the stack, below the filtered array. We make use of this by repeating the filtered array as many times as indicated by the ASCII code (*) before sorting it ($) and taking the last element (-1=). In effect, this yields the longest string in the filtered array (as they all consist of repeats of the same character, lexicographic sorting just sorts them by length), except if the character has ASCII code zero, in which case it yields nothing.

• Finally, the $ at the end just sorts the output alphabetically. 3Amazing. TODO: Learn GolfScript! – DLosc – 2014-04-13T02:38:07.813 1You may even reduce it to 26: n/:a{|}*{{{=}+,}+a%$-1=}%$. – Howard – 2014-06-05T09:41:05.423 13 # J - 37 char Reads from stdin, outputs to console. dlb#&a.>./+/"2=/&a.tolower;._2[1!:1]3  1!:1]3 is the call to stdin. tolower;._2 performs double duty by splitting up the lines and making them lowercase simultaneously. Then we count how many times a character occurs in each row with +/"2=/&a., and take the pointwise maximum over all lines with >./. Finally, we pull that many of each character out of the alphabet with #&a.. This includes spaces—all found at the front due to their low ASCII value—so we just delete leading blanks with dlb. 12 # JavaScript (ECMAScript 6) - 148139 135 Characters Version 2: Updated to use array comprehension: [a[i][0]for(i in a=[].concat(...s.split('\n').map(x=>x.split(/ */).sort().map((x,i,a)=>x+(a[i-1]==x?++j:j=0)))).sort())if(a[i-1]<a[i])]  Version 1: [].concat(...s.split('\n').map(x=>x.split(/ */).sort().map((x,i,a)=>x+(a[i-1]==x?++j:j=0)))).sort().filter((x,i,a)=>a[i-1]!=x).map(x=>x[0])  Assumes that: • The input string is in the variable s; • We can ignore the case of the input (as specified by the question - i.e. it is all in either upper or lower case); • The output is an array of characters (which is about as close as JavaScript can get to the OP's requirement of a list of characters); and • The output is to be displayed on the console. With comments: var l = s.split('\n') // split the input up into sentences .map(x=>x.split(/ */) // split each sentence up into letters ignoring any // whitespace .sort() // sort the letters in each sentence alphabetically .map((x,i,a)=>x+(a[i-1]==x?++j:j=0))) // append the frequency of previously occurring identical // letters in the same sentence to each letter. // I.e. "HELLO WORLD" => // ["D0","E0","H0","L0","L1","L2","O0","O1","R0","W0"] [].concat(...l) // Flatten the array of arrays of letters+frequencies // into a single array. .sort() // Sort all the letters and appended frequencies // alphabetically. .filter((x,i,a)=>a[i-1]!=x) // Remove duplicates and return the sorted .map(x=>x[0]) // Get the first letter of each entry (removing the // frequencies) and return the array.  If you want to: • Return it as a string then add .join('') on the end; • Take input from a user then replace the s variable with prompt(); or • Write it as a function f then add f=s=> to the beginning. Running: s="HELLO\nI LOVE CAT\nI LOVE DOG\nI LOVE MOMMY\nMOMMY LOVE DADDY"; [].concat(...s.split('\n').map(x=>x.split(/ */).sort().map((x,i,a)=>x+(a[i-1]==x?++j:j=0)))).sort().filter((x,i,a)=>a[i-1]!=x).map(x=>x[0])  Gives the output: ["A","C","D","D","D","E","G","H","I","L","L","M","M","M","O","O","T","V","Y","Y"]  [].concat(...s.splitN.map(x=>x.split(/ */).map((x,i,a)=>x+(a[x]=a[x]?++j:j=1)))).sort().map((x,i,a)=>a[i-1]<x?x[0]:'').join; – l4m2 – 2018-05-12T05:35:04.443 1Nice! You can save 3 bytes by reducing /\s*/ to / */ and removing the parens around j=0 – nderscore – 2014-04-11T06:16:08.303 1couldn't you use ... instead of apply ? – Ven – 2014-04-12T21:57:11.350 Thanks to you both - that saves 9 characters - The spread (...) operator is one I've not come across before. – MT0 – 2014-04-12T22:30:13.873 11 ## Perl - 46 bytes #!perl -p$s=~s/$_//ifor/./g;$s.=uc}for(sort$s=~/\w/g){  Counting the shebang as 1. This is a loose translation of the Ruby solution below. ## Ruby 1.8 - 72 bytes s='';s+=$_.upcase.scan(/./){s.sub!$&,''}while gets;$><<s.scan(/\w/).sort


Input is taken from stdin.

Sample usage:

$more in.dat Hello I love cat I love dog I love mommy Mommy loves daddy$ ruby fridge-letters.rb < in.dat
ACDDDEGHILLMMMOOSTVYY


Output needs to be sorted. – Matt – 2014-04-10T07:28:30.523

@Matt now fixed. – primo – 2014-04-10T08:04:36.073

Nice. If your Perl is vaguely recent though, you'll want a space between /i and for. – tobyink – 2014-04-10T13:45:32.517

8

# Python - 20620419917714512911794 88 chars

print(''.join(c*max(l.lower().count(c)for l in open(f))for c in map(chr,range(97,123))))


I wasn't sure how I was supposed to obtain the file name, so at the moment the code assumes that it is contained in a variable named f. Please let me know if I need to change that.

8in the spirit of unix - you could read from stdin. – romaninsh – 2014-04-10T07:02:41.630

5always make the file name one character long... – None – 2014-04-10T12:40:47.863

@professorfish is that the customary thing to do here? I'm still fairly new to this site – Tal – 2014-04-10T12:50:36.733

3@Tal I'm also new, but if it saves characters, why not? – None – 2014-04-10T12:54:28.517

@professorfish I felt that the "right" thing to do is replace that with proper input (argv, stdin, whatever), but that felt like a waste of characters, so I decided to just leave it – Tal – 2014-04-10T12:58:47.160

1By assuming f for the input filename and using uppercase (all magnet letters are uppercase anyway), you can get it down to 91: print(''.join([chr(i)*max(l.upper().count(chr(i))for l in open(f))for i in range(65,91)])) – Gabe – 2014-04-10T16:30:45.990

you can reduce by a few characters by using for i in string.uppercase rather than for i in range(65,91), as you wouldn't need the chr(i) (should be 6 characters less). Don't know if the import string shouldn't be counted too, though – njzk2 – 2014-04-11T14:33:08.103

(do we need the print, btw?) – njzk2 – 2014-04-11T14:35:10.233

1@njzk2 well, if we run this in the console, in theory it would just print the result by itself... – Tal – 2014-04-11T15:54:15.390

92 in Python 2: print ''.join([c*max(l.lower().count(c)for l in open('i'))for c in map(chr,range(97,123))]) – Cees Timmerman – 2014-04-11T16:41:40.003

My solution almost exactly. :) You can save two characters by eliminating the [] around the list comprehension: a comprehension, being iterable, can be passed directly to the join() function. – DLosc – 2014-04-13T02:32:51.457

I wonder if the output's format is totally necessary, I could just print the list and drop the ''.join – Tal – 2014-04-13T05:56:50.020

6

## Ruby 1.9+, 51 (or 58 or 60)

a=*$< ?a.upto(?z){|c|$><<c*a.map{|l|l.count c}.max}


Assumes everything's in lowercase. Case insensitivity costs 7 characters via .upcase, while case insensitivity and lowercase output costs 9 characters via .downcase.

4

# R (156, incl. file read)

With table I construct the letter frequency table for each sentence. Then I end up with taking for each letter the maximum value.

a=c();for(w in tolower(read.csv(fn,h=F)$V1))a=c(a,table(strsplit(w,"")[[1]]));a=tapply(seq(a),names(a),function(i)max(a[i]))[-1];cat(rep(names(a),a),sep="")  Ungolfed: a=c() words = read.csv(fn,h=F)$V1
for(w in tolower(words))
a=c(a, table(strsplit(w, "")[[1]]))
a = tapply(seq(a), names(a), function(i) max(a[i]))[-1] ## The -1 excludes the space count.
cat(rep(names(a), a), sep="")


Solution:

acdddeghillmmmoooooostuvyy


@lambruscoAcido you could vectorize the three first lines (of the ungolfed code) which would give you a=unlist(lapply(readLines(fn),function(x)table(strsplit(tolower(x),""))));a=tapply(seq(a),names(a),function(i)max(a[i]))[-1];cat(rep(names(a),a),sep=""), but it is only 3 characters shorter – jkd – 2018-02-28T20:48:20.667

Another approach with only 112 characters would be cat(unlist(sapply(letters,function(i)rep(i,max(sapply(gregexpr(i,readLines(f)),function(x)sum(x>0)))))),sep="") assuming f is the filename – jkd – 2018-02-28T20:49:55.583

4

import Data.List
import Data.Char
main=interact$sort.filter(/=' ').foldl1(\x y->x++(y\\x)).lines.map toLower  The program reads from stdin and writes to sdtout. It is quite straightforward: it breaks the string into a list of lines, and rebuilds it by iterating on the list and adding the new letters contained in each line. Oh wow why have I never heard of (\) before? – Flonk – 2014-04-10T15:18:57.807 – lortabac – 2014-04-10T15:50:18.250 4 # Perl 6: 5653 characters; 5855 bytes say |sort ([∪] lines.map:{bag comb /\S/,.lc}).pick(*)  For each line, this combs through it for the non-space characters of the lower-cased string (comb /\S/,.lc), and makes a Bag, or a collection of each character and how many times it occurs. [∪] takes the union of the Bags over all the lines, which gets the max number of times the character occurred. .pick(*) is hack-y here, but it's the shortest way to get all the characters from the Bag replicated by the number of times it occurred. EDIT: To see if it would be shorter, I tried translating histocrat's Ruby answer. It is 63 characters, but I still very much like the approach: $!=lines».lc;->$c{print$c x max $!.map:{+m:g/$c/}} for"a".."z"


3

Assuming the file is in file.txt!

import Data.Char
import Data.List


If file.txt contains, for example

abcde
abcdef
aaf


The script will output

aabcdef


Basically I'm appending the whole alphabet to each line, so that when grouping and sorting, I'm sure I'll end up with a list that contains 27 elements. Next, I transpose the "frequency table", so that each row in this array consists of the frequencies of a single letter in each line, e.g. ["a","","aaa","aa","aaaa"]. I then choose the maximum of each array (which works just like I want because of how the Ord-instance of Strings work), and drop the letter that I appended at the start, get rid of the spaces, and output the result.

1Instead of drop 1, just use tail – Bergi – 2014-04-10T23:55:42.647

@Bergi Haha derp, thanks! I changed it in the post. – Flonk – 2014-04-11T11:29:16.100

3

# Bash, 171159 158, 138 with junk output

Requires lowercase-only input. Assumes that the file is called _ (underscore). Maximum of 26 lines in the input file due to the annoying filenames which split creates (xaa, xab... xaz, ???).

In bash, {a..z} outputs a b c d e f ....

touch {a..z}
split _ -1
for l in {a..z}
do for s in {a..z}
do grep -so $l xa$s>b$l if [ wc -l<b$l -ge wc -l<$l ] then mv b$l $l fi done tr -d '\n'<$l
done


# Sample output

acdddeghillmmmoostvyy


# Explanation

touch {a..z}


Create files that we will be reading from later on so that bash doesn't complain that they don't exist. If you remove this line you will save 13 chars but get a lot of junk output.

split _ -1


Split the input file into sections, each storing 1 line. The files this command creates are named xaa, xab, xac and so on, I have no idea why.

for l in {a..z}
do for s in {a..z}


For each letter $l read through all lines stored in files xa$s.

do grep -so $l xa$s>b$l  Remove the -s switch to save 1 char and get a lot of junk output. It prevents grep from complaining about nonexistent files (will occur unless you have 26 lines of input). This processes the file xa$s, removing anything but occurences of $l, and sending output to the file b$l. So "i love mommy" becomes "mmm" with new lines after each letter when $l is m. if [ wc -l<b$l -ge wc -l<$l ]  If the number of lines in the file we just created is greater than or equal to (i.e. more letters since there is one letter per line) the number of lines in our highest result so far (stored in $l)...

then mv b$l$l


...store our new record in the file $l. At the end of this loop, when we have gone through all the lines, the file $l will store x lines each containing the letter $l, where x is the highest number of occurences of that letter in a single line. fi done tr -d '\n'<$l


Output the contents of our file for that particular letter, removing new lines. If you don't want to remove the new lines, change the line with tr to echo $l, saving 6 chars. done  Tried with GNU bash, version 3.2.51 (apple), but file '-l1aa' in a current folder containing input data.. – romaninsh – 2014-04-21T23:33:17.553 @romaninsh It might be that you have a different version of split (from coreutils). I am currently running GNU bash 4.3.8 and GNU coreutils 8.21 on Ubuntu 14.04 and it works fine (it also worked on Ubuntu 13.10 before I upgraded). However, I did have to place the program and the input file in a separate directory for it to work properly - I suspect this was only because of the millions of junk files in my home folder. – None – 2014-04-22T07:03:35.087 @romaninsh in fact, if you look at the exact command in the script: split _ -l1 and you notice that your input is being saved to -l1aa, I think that your version of split isn't recognising -l1 as an option and instead taking it to be a prefix for output. Try putting a space between -l and 1, or putting --lines=1, or just -1 (this appears to be an obsolete and more golfy syntax which I will now update the post with). – None – 2014-04-22T07:06:26.903 3 C, 99 chars t[256];main(c){for(--*t;++t[1+tolower(getchar())];);for(c=97;c<123;c++)while(t[c]--)putchar(c-1);}  It crashes if less than one newline is provided. I think it could be fixed quite easily. I tried, but it didn't produce correct results. https://gist.github.com/romaninsh/11159751 – romaninsh – 2014-04-21T23:15:18.823 3 ## kdb (q/k): 59 characters: d:.Q.a! 26#0 .z.pi:{d|:.Q.a##:'=_y}.z.exit:{-1@,/.:[d]#'!:d}  • generate pre-sorted seed dictionary from alphabet .Q.a • process each line of input, convert to lowercase, group into dictionary, count each element, take alphabetic characters from result (I.e. prune spaces, newlines, etc at this stage) and use max-assign to global d to keep a running total. • define exit handler, which gets passed in to .z.pi to save a delimiter but otherwise unused there. Take from each key-value to generate list of characters, flatten and finally print to stdout. -1 adds a newline, using 1 would save a character but does not generate the output specified. Wish I could get rid of the .z.pi / .z.exit boilerplate, which would remove 14 characters. Edit: avoid use of inter/asc by using seed dictionary. 3 ## Perl, 46 for$:(a..z){$a[ord$:]|=$:x s/$://gi}}{print@a


Here's another Perl solution, reads from STDIN, requires -n switch (+1 to count), ties with primo's score but runs without complaints :-). It exploits the fact that bitwise or's result has longer string argument's length.

1tried with my test and it worked great. – romaninsh – 2014-04-21T23:37:06.460

3

## C#, 172 bytes

var x="";foreach(var i in File.ReadAllText(t).ToLower().Split('\r','\n'))foreach(var j in i)if(x.Count(c=>c==j)<i.Count(c=>c==j))x+=j;string.Concat(x.OrderBy(o=>o)).Trim();


Clever ...clever ... I thought about playing with linq, but doubt it'll be as short as these contorted foreachs :) – Noctis – 2014-04-14T06:42:51.347

3

## Bash - 72

Assumes that input is in file "i"

gc a|%{[char[]]$_|group|%{$c=$_.name.tolower().trim()$n=$_.count;$x[$c]=($n,$x[$c])[$n-lt$x[$c]]}} ($x.Keys|sort|%{$_*$x[$_]})-join""  2 # Bash (mostly awk) - 172163 157 awk -v FS="" '{delete l;for(i=1;i<=NF;i++)l[toupper($i)]++;for(i in l)o[i]=(o[i]>l[i]?o[i]:l[i])}END{for(i in o)for(j=0;j<o[i];j++)print i}'|sort|tr -d ' \n'


Text needs to be piped in to awk (or specified as a file).

### Example Input

Hello
I love cat
I love dog
I love mommy


### Example Output

ACDDDEGHILLMMMOOSTVYY


# PHP (probably could be better) - 174 210

$o=array();foreach(explode("\n",$s) as $a){$l=array();$i=0;while($i<strlen($a)){$k=ucfirst($a[$i++]);if($k==' ')continue;$o[$k]=max($o[$k],++$l[$k]);}}ksort($o);foreach($o as$k=>$v)for($i=0;$i<$v;$i++)echo$k;


$i=explode("\n",$s);foreach(range('a','z')as$c){$x=array_map(function($l)use($c){return substr_count($l,$c);},$i);echo str_repeat($c,max($x));}  ## Explanation For each possible letter I'm mapping array containing list of strings through a user-defined function which replaces each line with number of characters used. For letter 'd' the line "Mommy loves daddy" will be mapped into 3. Afterwards I find maximum value inside array and output letter just this many times. Here is multi-line version: $i=explode("\n",$s); foreach(range('A','Z')as$c){
$x=array_map(function($l)use($c){ return substr_count($l,$c); },$i);
echo str_repeat($c,max($x));
}


2

# K, 34

{$a@<a:,/(.:a)#'!:a:|/#:''=:'0:x}  1 # Japt v1.4.5, 11 bytes ;CËpUmèD rw  Try it online! ### Unpacked & How it works ;CmDEF{DpUmèD rw ; Use an alternative set of predefined variables C "abc...z" mDEF{ Map over each char and form a string... UmèD Map over input array into char count rw Reduce with max Dp Repeat the char this number of times  1 # Python (209, with the sample included, 136 without.): from collections import*;c=Counter() for i in ["Hello","I love cat", "I love Dog", "I love mommy", "Mommy loves daddy"]: for j in i.lower(): c[j]=max(c[j],list(i).count(j)) print "".join(sorted(c.elements()))  I'll post a PYG sample this afternoon. I had no idea Python strings had a count method... I don't suppose it's considered legit to change my answer to the question to use this new found knowledge? :p – Tal – 2014-04-10T07:16:12.940 @tal They don't. It's a method of a list, if you look closer – ɐɔıʇǝɥʇuʎs – 2014-04-10T07:17:42.543 1Oh, I see... but in an unexpected twist it turns out strings apparently have this method as well (in 3.x anyway) – Tal – 2014-04-10T07:22:02.280 1 # JavaScript - 244 Accepts a parameter of string with newlines. function s(z){n=m="",y=[];z.toLowerCase().split("\n").map(function(g){a=[];g.replace(/ /g,n).split(n).map(function(e,i){if((+y[e]|0)<(a[e]=(+a[e]|0)+1))y[e]=a[e];});});for(var b in y){m+=Array(y[b]+1).join(b);}return m.split(n).sort().join(n);}  Not happy with the sorting and preparation of the output. Edit: case-insensitive regex unnecessary! Thanks @Bergi 2Upper- and lowercase spaces in that regex? – Bergi – 2014-04-10T23:59:07.890 1 # C++, 264 characters. Reads lowercase text from standard input. #include<algorithm> #include<iostream> #include<map> using namespace std;main(){string s;map<int,long> m;while(getline(cin,s)){int c='';while(c++<'z')m[c]=max(m[c],count_if(begin(s),end(s),[c](int d){return d==c;}));}for(auto i:m)cout<<string(i.second,i.first);}  # C++ function, 205 characters. string a(istream&i){string s;map<int,long> m;while(getline(i,s)){int c='';while(c++<'z')m[c]=max(m[c],count_if(begin(s),end(s),[c](int d){return d==c;}));}for(auto i:m)s.append(i.second,i.first);return s;}  1 # JavaScript, 199 characters function(n){for(s in p=n.toUpperCase(t=[]).split("\n"))for(i in p[k={},s])t[l=p[s][i]]=Math.max(t[l]||0,k[l]=k[l]+1||1);for(l in t)t.push(new Array(t[l]+1).join(l));return t.sort().join('').trim()}  In Chrome 33, doing for(..in..) on a string results in function properties being accessed. It breaks this solution. The example input from OP gives this result: "ACDDDEGHILLMMMOOSTVYYfunction (){var e=this.toString();if(!arguments.length)return e;var t=typeof arguments[0],n="string"==t||"number"==t?Array.prototype.slice.call(arguments):arguments[0];for(var i in n)e=e.replace(new RegExp("\\{"+i+"\\}","gi"),n[i]);return e}function (e){return this.indexOf(e)>-1}function (e){var t=this.lastIndexOf(e);return 0>t?[this]:[this.substr(0,t),this.substr(t)]}function (e,t){var n=this.toString();re... – nderscore – 2014-04-10T19:56:59.737 1 # Lua - 206 Chars g=string f,t,b,e=io.lines(({...})[1]),{},g.byte,g.char for s in f do for c=b"a",b"a" do _,d=s:lower():gsub(e(c),"");t[c]=t[c]and(t[c]>d and t[c])or d end end for c=b"a",b"z" do io.write(g.rep(e(c),t[c]))end  Reads from the file passed via command line, then creates a table with the maximum number of occurences per letter. Finally outputs the occuring letters. 1 # Julia, 159 My objective is help understand/improve the expressiveness of Julia. Here's a first attempt. a='a'-1;print(foldl((c,n)->(global a+=1;"$c"*"$a"^n),"",int(mapreduce(s->hist(int({s...}),0:255)[2],(S,T)->max(S,T),zeros(255),readlines(STDIN))[97:122]))"\n")  Here's my crazy idea. Using mapreduce, foldl, and hist (builtin histogram) were advantageous, but having to deal assembling an array from a string and then back to a string from an array and globals expanded the length. Program reads from STDIN. Required foldl which is new in Julia 0.30. ### Sample Input alskdja flkjaslakjd asa as g alkdjaslkajsd  Output aaaddfgjjkkllss  1 # Java, 335 Here is the executable code in java in a more readable form. Once all the unnecessary white spaces are removed, you will see 335 characters in all. The output is: ACDDDEGHILLMMMOOSTVYY It gets a filename as input and reads each character from the file, converts it to uppercase and stores the count of it's occurrence in an array. For every new line, the maximum occurrence of each character is updated. At last it is printed. Pre-requiste: The file should end with a newline. class F { public static void main(String[] a) throws Exception { java.io.FileInputStream f = new java.io.FileInputStream(a[0]); int j, r, l = 256; int[] i = new int[l], t = new int[l]; while ((r = f.read()) > 0) { r = r > 96 ? r - 32 : r; if (r == 10) for (j = 0; j < l; j++) { i[j] = i[j] < t[j] ? t[j] : i[j]; t[j] = 0; } else t[r]++; } for (j = 65; j < 91; j++) while (i[j]-- > 0) System.out.print((char) j); } }  After removing the white spaces the code will look like the following: class F{public static void main(String[] a)throws Exception{java.io.FileInputStream f=new java.io.FileInputStream(a[0]);int j,r,l=256;int[] i=new int[l],t=new int[l];while((r=f.read())>0){r=r>96?r-32:r;if(r==10)for(j=0;j<l;j++){i[j]=i[j]<t[j]?t[j]:i[j];t[j]=0;}else t[r]++;}for(j=65;j<91;j++)while(i[j]-->0)System.out.print((char)j);}}  1 # C#, 265 characters Assuming input is in variable s, here's a C# Expression, using mainly LINQ (Enumerable.cs): string.Join("",s.ToLower().Split('\n').Select(e=>e.Where(l=>l!=' '&&l!='\r') .GroupBy(l=>l).ToDictionary(k=>k.Key,v=>v.Count())).SelectMany(u=>u).GroupBy(l=>l.Key) .Select(g=>new String(Enumerable.Range(1,g.Max(v=>v.Value)).Select(i=>g.Key).ToArray())) .OrderBy(l=>l))  0 # Kotlin, 189 bytes lines().map{it.filter{it.isLetter()}.groupingBy{it}.eachCount()}.fold(mutableMapOf<Char,Int>()){r,i->i.map{(t,u)->r[t]=maxOf(r[t] ?:0,u)} r}.flatMap{(k,v)->(0..v-1).map{k}}.joinToString("")  ## Beautified lines() .map { it.filter { it.isLetter() }.groupingBy { it }.eachCount() } .fold(mutableMapOf<Char, Int>()) { r, i -> i.map { (t, u) -> r[t] = maxOf(r[t] ?: 0, u)} r } .flatMap { (k, v) -> (0..v-1).map { k } } .joinToString("")  ## Test fun String.f() = lines().map{it.filter{it.isLetter()}.groupingBy{it}.eachCount()}.fold(mutableMapOf<Char,Int>()){r,i->i.map{(t,u)->r[t]=maxOf(r[t] ?:0,u)} r}.flatMap{(k,v)->(0..v-1).map{k}}.joinToString("") fun main(args: Array<String>) { val i = """hello i love cat i love dog i love mommy mommy loves daddy""" println(i.f().map { it }.sorted().joinToString("")) println("acdddeghillmmmoostvyy") }  ## TIO TryItOnline 0 # Haskell, 41 bytes f s=do c<-['a'..];maximum$filter(==c)<$>s  Try it online! f takes a list of lines as input. Add main=interact$f.lines to get a full program for a total of 63 bytes.

Explanation

f s=                -- input s is the list of lines
do c<-['a'..];     -- for each char c starting at c='a', concatenate the following strings
filter(==c)<$>s -- for each line in s remove all characters except for the current c maximum$         -- take the longest of those strings


0

# Stax, 8 bytes

ü2lLÜ▀⌂æ


Run and debug it

1. Reduce the array of inputs using a multiset union operation.
2. Sort the resulting characters.
3. Remove spaces.

0

# Powershell, 118116 87 bytes

-join($args|%{$_|% t*y|group|%{-join$_.Group}}|sort|group{$_[0]}|%{$_.Group[-1]})|% t*m  Less golfed test script: $f = {

$x=$args|%{$_|% t*y|group|%{-join$_.Group}} # unsorted groups of the same letters for each sentence: (h,e,ll,o), (...), (...), (i, ,l,oo,v,e,d,g),...
$y=$x|sort|group{$_[0]} # sort all groups and group it again by the first letter (( , , , ), (a,a), (c), (d,ddd), ... (y,yy))$z=$y|%{$_.Group[-1]}                       # get a last item (maximum item) from each group
-join($z)|% t*m # join it and trim spaces } @( ,("acdddeghillmmmoostvyy", "hello", "i love cat", "i love dog", "i love mommy", "mommy loves daddy") ,("AAAAAAAAAAAAAAAABBBCCCCDDDDDEEEEEEEEEFFGGGGHHHHHHIIIIIIIIIIJJKKLLLLMMMMMMMNNNNNNNNNNNNNOOOOOOOOOPPPPPPPQRRRRRRSSSSSSSTTTTTTUUUUUVWWXYYY", "I SAW THE MAN WITH THE BINOCULARS", "THEY ARE HUNTING DOGS", "FREE WHALES", "POLICE HELP DOG BITE VICTIM", "HE SAW THAT GAS CAN EXPLODE", "TURN RIGHT HERE", "WE SAW HER DUCK", "IN ANIMAL CRACKERS GROUCHO MARX AS CAPTAIN RUFUS T SPAULDING QUIPPED ONE MORNING I SHOT AN ELEPHANT IN MY PAJAMAS HOW HE GOT IN MY PAJAMAS I DONT KNOW", "SHIP SAILS TOMORROW", "BOOK STAYS IN LONDON", "WANTED A NURSE FOR A BABY ABOUT TWENTY YEARS OLD", "THE GIRL IN THE CAR THAT NEEDED WATER IS WAITING", "DID YOU EVER HEAR THE STORY ABOUT THE BLIND CARPENTER WHO PICKED UP HIS HAMMER AND SAW", "THOSE PROSECUTORS HAVE BEEN TRYING TO LOCK HIM UP FOR TEN YEARS", "FLYING PLANES CAN BE DANGEROUS", "I ONCE SAW A DEER RIDING MY BICYCLE", "TOILET OUT OF ORDER PLEASE USE FLOOR BELOW", "LOOK AT THE DOG WITH ONE EYE") ) | %{$expected,$s =$_
$result = &$f @s
"$($result-eq$expected):$result"
}


Output:

True: acdddeghillmmmoostvyy


0

# Jelly, 7, 6, 5 or 4 bytes

ỴŒuœ|/Ṣ


Try it online!

Function submission. Depending on how you interpret the I/O rules, it may be possible to drop the leading Ỵ (which would then require input to be the data structure "list of strings", as opposed to a single string that was divided using newlines); and it may be possible to drop the Œu (which would then require the input to use a consistent case for the output to be correct).

## Explanation

ỴŒuœ|/Ṣ
Ỵ        Split on newlines
Œu      Uppercase each resulting string
/   Combine the resulting strings using…
œ|      …multiset union
Ṣ  Sort


Many answers interpret ignore cases, all magnet letters are capitals anyway as that we don't have to handle input with different cases. The fact that the test case uses lowercase letters supports this interpretation. – Dennis – 2018-12-13T19:04:01.060

I interpreted the question as requiring you to standardise case (although it didn't matter whether you used uppercase or lowercase). Without that, you can obviously drop the Œu for a 5 or 4 byte solution. – ais523 – 2018-12-13T19:06:09.533

0

# PHP, 116 bytes

foreach(file(T)as$y=>$s)for($i=0;~$c=ucfirst($s[$i++]);)$$c[y]++;for(c=A;!c[1];c++)echo str_repeat(c,max($$c));


assumes filename T. Run with -nr.

breakdown

foreach(file(T)as$y=>$s)            # loop through lines of file
for($i=0;~$c=ucfirst($s[$i++]);)    # loop through line characters
$$c[y]++; # increment counter (A..Z) for(c=A;!c[1];c++) # loop c through uppercase letters echo str_repeat(c,max($$c));      # get max from $A,$B etc, use as multiplier for str_repeat


0

# 05AB1E, 12 bytes

εAS¢}ø€àAS×J


I have the feeling this can be golfed by at least a few bytes..

Input taken as a list of lowercase strings. If taking the input as a newline-delimited string and with mixed case is mandatory, two more bytes should be added.

Try it online.

Explanation:

ε   }         # Map each string in the (implicit) input-list to:
A            #  Push the lowercase alphabet
S           #  as a list of characters
¢          #  And get the count of each letter in the map-string
#   i.e. ["hello","i love cat","i love dog","i love mommy","mommy loves daddy"]
#    → [[0,0,0,0,1,0,0,1,0,0,0,2,0,0,1,0,0,0,0,0,0,0,0,0,0,0],[1,0,1,0,1,0,0,0,1,0,0,1,0,0,1,0,0,0,0,1,0,1,0,0,0,0],[0,0,0,1,1,0,1,0,1,0,0,1,0,0,2,0,0,0,0,0,0,1,0,0,0,0],[0,0,0,0,1,0,0,0,1,0,0,1,3,0,2,0,0,0,0,0,0,1,0,0,1,0],[1,0,0,3,1,0,0,0,0,0,0,1,3,0,2,0,0,0,1,0,0,1,0,0,2,0]]
ø        # Zip/transpose; swapping rows/columns
#  → [[0,1,0,0,1],[0,0,0,0,0],[0,1,0,0,0],[0,0,1,0,3],[1,1,1,1,1],[0,0,0,0,0],[0,0,1,0,0],[1,0,0,0,0],[0,1,1,1,0],[0,0,0,0,0],[0,0,0,0,0],[2,1,1,1,1],[0,0,0,3,3],[0,0,0,0,0],[1,1,2,2,2],[0,0,0,0,0],[0,0,0,0,0],[0,0,0,0,0],[0,0,0,0,1],[0,1,0,0,0],[0,0,0,0,0],[0,1,1,1,1],[0,0,0,0,0],[0,0,0,0,0],[0,0,0,1,2],[0,0,0,0,0]]
€à      # Leave the maximum of each
#  → [1,0,1,3,1,0,1,1,1,0,0,2,3,0,2,0,0,0,1,1,0,1,0,0,2,0]
AS×   # Repeat each the letters of the alphabet amount of times
#  → ["a","","c","ddd","e","","g","h","i","","","ll","mmm","","oo","","","","s","t","","v","","","yy",""]
J  # And join everything together (which is output implicitly)
#  → "acdddeghillmmmoostvyy"


0

# JavaScript, 105 104 bytes

Takes input as an array of character arrays and returns a string.

a=>[...new Set(a+)].sort().map(c=>c.repeat(a.map(r=w=>r=w.map(l=>o+=c>{}&c==l,o=0)|o<r?r:o)|r)).join


Try it online

0

# Pyth, 14 10 bytes

smeS@Ld.zG


Accepts input as lowercase strings. Try it online here.

smeS@Ld.zG   Implicit: .z=input as list of strings, G=lowercase alphabet
m       G   Map each letter in G, as d, using:
L .z      In each string in .z ...
@ d        ... keep only those characters which match d
S           Sort by length
e            Take the last element (i.e. longest)
s            Concatenate into string, implicit print


Edit: golfed 3 bytes. Previous version: sm*deSml@dk.zG

0

# C, 298 bytes

(242 bytes by not counting newlines)

Array D keeps tally of letters in each line, then the maximum count of each letter is copied into array C.

char c;
int j,n;
char C[26];
char D[26];
int main()
{
char a='a';
while((c=getchar())>=0)
{
c=tolower(c);
if(c>=a&&c<='z'){j=c-a;D[j]++;}
if(c=='\n'){
for(j=0;j<26;j++){
if(D[j]>C[j])
{C[j]=D[j];}
D[j]=0;
}
}
}
for(j=0;j<26;j++)
{
n=C[j];
while(n--)
{
putchar(a+j);
}
}
}


Note: I just discovered Notepad++ which gives my character count, counts newlines as 2 chars. Should these be subtracted?

That's because you use CRLF (Windows) line terminators. You should tell Notepad++ to use LF (Unix), then they will only count as one character. – nyuszika7h – 2014-04-21T20:00:37.463

0

# C# / LINQPad, 181 bytes

In C# Expression mode; assumes input file is named a (and probably in the LINQPad Program Files folder)

string.Join("",File.ReadAllLines("a").SelectMany(s=>s.ToUpper().Where(c=>c>64&&c<91).GroupBy(c=>c)).GroupBy(g=>g.Key).Select(g=>new string(g.Key,g.Max(x=>x.Count()))).OrderBy(s=>s))


### Ungolfed

string.Join("",                                                     // concat all substrings, with no separator
.SelectMany(                                                // apply function to each subset and union into a single set
s => s.ToUpper()                                        // convert strings to uppercase
.Where(c => c > 64 && c < 91)                     // shorter than char.IsLetter(c) for all uppercase
.GroupBy(c => c)                                  // group on each character in the string
)
.GroupBy(g => g.Key)                                        // group again on each character (I'd love to get rid of this...)
.Select(g => new string(g.Key, g.Max(x => x.Count())))      // string(char, count) constructor build repeating-char string
.OrderBy(s => s)                                            // sorted set required
)


### Input (text file called a)

Hello
I love cat
I love dog
I love mommy


### Output

ACDDDEGHILLMMMOOSTVYY


0

# C# - 146 Bytes

var x="";foreach(var l in File.ReadAllLines(t))foreach(var p in l)if(x.Count(c=>c==p)<l.Count(c=>c==p))x+=p;string.Concat(x.OrderBy(o=>o)).Trim();
`

Well, I think this is as short as C# can get. This code expects a path to the text file in the variable t.