Calculate your stack exchange reputation

Question

Background:

I often find that, when browsing a Stackexchange site, I begin to wonder how people get the amount of reputation that they have. I know I can always count on codegolf SE to solve my problems, so here it is:

Create a program that will accept a positive integer which represents a person's reputation. We will ignore bounties, and say that these are the only ways to gain/lose rep on SE (full table here):

• Every account starts out with 1 rep and cannot go below that
• Your question is upvoted = +5
• Your answer is upvoted = +10
• Your question is downvoted = -2
• Your answer is downvoted = -2
• You downvote an answer = -1
• Your answer is accepted = +15
• You accept an answer = +2

Your program must figure out how many of those actions occurred on that user's account to get to the rep they have. It must figure out the shortest number of actions to get to this level of rep. Examples:

Input: 11 Output: 1 answer upvote

Input: 93 Output: 6 answer accepts, 1 answer accepted

In these examples when I say 'question upvote', it means that person's queston got upvoted. When I say 'answer downvoted', it means they downvoted someone else's answer.

Rules:

code-golf, so the shortest code that can do this wins.

Answer 1

Golfscript, 162 144 bytes

{{}if}:?;~.)15/:^15*-:~3>1~8>' answer ':A' question 'if'upvote'++?^^A'accept'+:C+^1>{'s'+}??~5%:,4<,1>&1C'ed'++?,2%!1A'downvote'++,4<{'d'+}??]n*

How it works

The general idea is exactly the same as in my Bash answer.

{{}if}:?;         # Create an `if' statement with an empty `else' block.
                  #
~.)15/:^          # Interpret the input string, subtract 1 from its only element (the
                  # reputation score), divide by 15 and save the result in `^'. This gives
                  # the number of accepted answers.
                  #
15*-:~            # Multiply the number of accepted answer by 15 and subtract the product
                  # from the reputation score. Save the result in `~'.
                  #
3>                # If the result is greater than 3:
                  #
  1               # Push 1 on the stack.
                  #
  ~8>             # If the result is greater than 8:
                  #
    ' answer ':A  # Push `answer' on the stack. Either way, save the string in `A'.
                  #
    ' question '  # Otherwise, push `question' on the stack.
                  #
  if              #
                  #
  'upvote'++      # Push `upvote' on the stack and concatenate the three strings.
                  #
?                 #
                  #
^                 # If the number of accepted answers is positive:
                  #
  ^A'accept'+:C+  # Push the number, concatenated with the string ` answer accept', on the
                  # stack. Either way, the string in `C'.
                  #
  ^1>             # If the number of accepted answers is greater than 1:
                  #
    {'s'+}        # Cocatenate the previous string with `s', for proper pluralization.
                  #
  ?               #
                  #
?                 #
                  #
~5%:,             # Calculate the reputation score modulus 5. Save the result in `,'.
                  #
4<,1>&            # If the result is less than 4 and greater than 1:
                  #
  1C'ed'++        # Push the string `1 answer accepted' on the stack.
                  #
?                 #
                  #
,2%!              # If the result is odd:
                  #
  1A'downvote'++  # Push the string `1 answer downvote' on the stack.
                  #
  ,4<             # If the result is less than 4:
                  #
    {'d'+}        # Concatente the previous string with `d'.
                  #
  ?               #
                  #
?                 #
                  #
]n*               # Join the array formed by all strings on the stack, separating the
                  # strings by newlines. This is the output.

Answer 2

Bash, 247 202 192 bytes

n=$1 bash <(sed 's/E/)echo /;s/C/ Aaccept/;s/A/answer /
s/.*)/((&)\&\&/'<<<'a=(n+1)/15,a-1)s=s;q=question
aE$aC$s
r=n%5,r-4)d=d&&
r>1E1Ced
1-r%2E1 Adownvote$d
n-=15*a,n>8)q=A
n>3E1 $q upvote')

How it works

After the sed command does it job, the following bash script gets executed:

((a=(n+1)/15,a-1))&&s=s;q=question
((a))&&echo $a answer accept$s
((r=n%5,r-4))&&d=d&&
((r>1))&&echo 1 answer accepted
((1-r%2))&&echo 1 answer downvote$d
((n-=15*a,n>8))&&q=answer 
((n>3))&&echo 1 $q upvote

To obtain the optimal solution (minimal number of events to get n reputation), it suffices to compute the number of accepted answers (a) necessary to get to a reputation below 16 (1 answer accept) and handle the residue as follows:

1  (no rep change)
2  answer accepted, answer downvoted
3  answer accepted
4  question upvote, answer downvote
5  question upvote, answer downvoted
6  question upvote
7  question upvote, answer accepted, answer downvoted
8  question upvote, answer accepted
9  answer upvote, answer downvote
10 answer upvote, answer downvoted
11 answer upvote
12 answer upvote, answer accepted, answer downvoted
13 answer upvote, answer accepted  
14 answer accept, answer downvote
15 answer accept, answer downvoted

Answer 3

Perl, 500 263 256 208 bytes

Script rep.pl:

$_=1+pop;sub P($){print$=,@_,$/}$;=" answer ";$:="$;downvote";($==$_/15)&&P"$;accept"."s"x($=>1);$_%=15;$==1;P"$;upvote",$_-=10if$_>9;P" question upvote",$_-=5if$_>4;P"$;accepted"if$_>2;P$:."d"if$_%2;P$:if!$_

Usage

The input is expected as positive integer, given as argument to the script. The different actions are output as lines.

Tests

perl rep.pl 11
1 answer upvote

perl rep.pl 93
6 answer accepts
1 answer accepted

perl rep.pl 1

perl rep.pl 4
1 question upvote
1 answer downvote

perl rep.pl 12
1 answer upvote
1 answer accepted
1 answer downvoted

perl rep.pl 19
1 answer accept
1 question upvote
1 answer downvote

perl rep.pl 34
2 answer accepts
1 question upvote
1 answer downvote

perl rep.pl 127
8 answer accepts
1 question upvote
1 answer accepted
1 answer downvoted

perl rep.pl 661266
44084 answer accepts
1 question upvote

Ungolfed

$_ = pop() + 1; # read the reputation as argument,
                # remove the actionless start reputation
                # and add a bias of two to calculate
                # the answer accepts in one division.

# Actions
# -------
# answer accepts:      Your answer is accepted    = +15
# answer upvotes:       Your answer is upvoted     = +10
# question upvotes:     Your question is upvoted   = +5
# answers accepted:     You accept an answer       = +2
# answers downvoted:    You downvote an answer     = -1
# answer downvotes:     Your answer is downvoted   = -2
# (questions downvoted: Your question is downvoted = -2) not used

# Function P prints the number of actions in $= and
# the action type, given in the argument.
# The function is prototyped "($)" to omit the
# parentheses in the usage.
sub P ($) {
    print $=, @_, $/ # $/ is the line end "\n"
}
# abbreviations,
# special variable names to save a space if a letter follows
$; = " answer ";
$: = "$;downvote";

# Calculation and printing the result
# -----------------------------------
($= = $_ / 15) && # integer division because of the special variable $=
P "$;accept" .
  "s" x ($= > 1); # short for: ($= == 1 ? "" : "s")
$_ %= 15;
$= = 1;           # now the action count is always 1 if the action is used
P "$;upvote",         $_ -= 10 if $_ > 9;
P " question upvote", $_ -=  5 if $_ > 4;
P "$;accepted"                 if $_ > 2;
P $: . "d"                     if $_ % 2;
P $:                           if ! $_

Older version

$_ = pop() + 1; # read the reputation as argument
                # subtract start reputation (1)
                # add bias (2)

# Actions
# -------
# $= answer accepts:      Your answer is accepted    = +15
# $b answer upvotes:      Your answer is upvoted     = +10
# $c question upvotes:    Your question is upvoted   = +5
# $d answers accepted:    You accept an answer       = +2
# $e answers downvoted:   You downvote an answer     = -1
# $f answer downvotes:    Your answer is downvoted   = -2
# -- questions downvoted: Your question is downvoted = -2

# Calculaton of answer accepts by a simple division that is
# possible because of the bias.
$= = $_ / 15; # integer division because of the special variable $=
$_ %= 15;

# The older version of the calculation can be simplified further, see below.
# Also the older version did not use the bias.
#
# function E optimizes the construct "$_ == <num>" to "E <num>"
# sub E {
#     $_ == pop
# }
#
# $d = $e = 1 if E 1;       #  1 =     +2 -1
# $d++ if E 2;              #  2 =     +2
#
# $c = $f = 1 if E 3;       #  3 =  +5 -2
# $c = $e = 1 if E 4;       #  4 =  +5 -1
# $c++ if E 5;              #  5 =  +5
# $c = $d = $e = 1 if E 6;  #  6 =  +5 +2 -1
# $c = $d = 1 if E 7;       #  7 =  +5 +2
#
# $b = $f = 1 if E 8;       #  8 = +10 -2
# $b = $e = 1 if E 9;       #  9 = +10 -1
# $b++ if E 10;             # 10 = +10
# $b = $d = $e = 1 if E 11; # 11 = +10 +2 -1
# $b = $d = 1 if E 12;      # 12 = +10 +2
#
# $=++, $f++ if E 13;       # 13 = +15 -2
# $=++, $e++ if E 14;       # 14 = +15 -1

$b++, $_ -= 10 if $_ > 9;
$c++, $_ -=  5 if $_ > 4;

# Now $_ is either 0 (-2), 1 (-1), 2 (0), 3 (1), or 4 (2).
# The number in parentheses is the remaining reputation change.

# The following four lines can be further optimized. 
# $f++        if ! $_;    # "! $_" is short for "$_ == 0"
# $e++        if $_ == 1;
# $d = $e = 1 if $_ == 3;
# $d++        if $_ == 4;

# Optimized version of the previous four lines:

$f++ if ! $_;
$e++ if $_ % 2;
$d++ if $_ > 2;

# function P optimizes the printing and takes the arguments for "print";
# the first argument is the action count and the printing is suppressed,
# if this action type is not needed.
sub P {
    print @_, $/ if $_[0]
    # $/ is "\n"
}

# some abbreviations to save some bytes
$; = " answer ";
$D = "$;downvote";

# output the actions

P $=, "$;accept", ($= == 1 ? "" : "s");
P $b, "$;upvote";
P $c, " question upvote";
P $d, "$;accepted";
P $e, $D, "d";
P $f, $D

Edits

• Case 4 is fixed.
• This also simplifies the calculation that is now done without a loop.
• Unreachable plural "s" removed, function S no longer needed.
• Calculation optimized, function E no longer needed.
• Bias of 2 added for optimized calculation.
• Larger rewrite to remove most variables some other tricks to save some bytes.

Answer 4

R, 454 421

r=as.integer(commandArgs(T)[1])-1;p=function(...){paste(...,sep='')};a='answer ';b='accept';e='ed';f='d';v='vote';d=p('down',v);u=p('up',v);q='question ';z=c();t=r%/%15;if(t>0){z=c(p(t,' ',a,b));r=r%%15;};if(r%in%(8:12))z=c(z,p(a,u));if(r%in%(3:7))z=c(z,p(q,u));if(r%in%c(1,2,6,7,11,12))z=c(z,p(a,b,e));if(r%in%(13:14))z=c(z,p(a,b));if(r%in%c(3,8,13))z=c(z,p(a,d));if(r%in%c(1,4,6,9,11,14))z=c(z,p(a,d,f));cat(z,sep=', ')

Thanks to Dennis for his answer which helped me a lot.

Ungolfed version

# read input
r = as.integer(commandArgs(T)[1]) - 1

# shortcut to join strings (... will pass the parameter to paste() *as is*)
p = function(...) {paste(..., sep = '')}

# strings
a = 'answer '; b = 'accept'; e = 'ed'; f = 'd'
v = 'vote'; d = p('down',v); u = p('up',v)
q = 'question '

z = c()

# +15
t = r %/% 15;
if (t > 0) {
    z = c(p(t,' ',a,b))
    r = r %% 15
}

if (r %in% (8:12))              z = c(z,p(a,u));    # answer upvote
if (r %in% (3:7))               z = c(z,p(q,u));    # question upvote
if (r %in% c(1,2,6,7,11,12))    z = c(z,p(a,b,e));  # answer accepted
if (r %in% (13:14))             z = c(z,p(a,b));    # answer accept
if (r %in% c(3,8,13))           z = c(z,p(a,d));    # answer downvote
if (r %in% c(1,4,6,9,11,14))    z = c(z,p(a,d,f));  # answer downvoted

# print operations
cat(z,sep = ', ')

Answer 5

JavaScript - 270 237 227 206 192 characters

p=prompt,r=p()-1,a="1answer ",v="vote,";s=(r/15|0)+"answer accept,",r%=15;if(r>9)s+=a+"+"+v,r-=10;if(r>2)s+="1question +"+v,r-=5;r>0?s+=a+"accepted,":0;r<-1?s+=a+"-"+v:0;p(r&1?s+=a+"-voted":s)

Exactly as many chars as Bash (yeah!), and beats Python and Perl :) It cuts down the reputation until 14 after which it takes after which it takes the other necessary actions, completely loop-style.

EDIT 1: Converted \ns to ,s and converted one if block to ternary, and better flooring with short names.

EDIT 2: Big thanks to Alconja who helped me cut down 11 chars. After which I made some more corrections to cut down 2 more chars.

---

Older Version:

r=prompt()-1,a="1answer ",q="1question ",v="vote,";s=(c=r/15|0)+"answer accept,",r-=c*15;if(r>9)s+=a+"+"+v,r-=10;if(r>2)s+=q+"+"+v,r-=5;r>0?s+=a+"accepted,":0;if(r<-1)s+=a+"-"+v;r&1?s+=a+"-voted":0;alert(s)

---

Test:

INPUT: 42
OUTPUT:

2answer accept,1answer +vote,1answer accepted,1answer -voted

/*I sincerely hope the output is clear and easy to make out*/

INPUT: 1337
OUTPUT:

89answer accept,1answer accepted,1answer -voted

---

Ungolfed Code:

// different version from the golfed code
rep = prompt() - 1
string = ""

function $(z, c, k){
  while(rep > 0 && rep >= z - 2) c += 1 , rep -= z;

  if(c) string += c + k + "\n"
}

a=" answer ", q=" question "

$(15, 0, a + "accept")
$(10, 0, a + "upvote")
$(5, 0, q + "upvote")
$(2, 0, a + "accepted")

function _(z, c, str){
  while(rep <= z) c += 1, rep -= z

  if(c) string += c + str + "\n";
}

_(-2, 0, a + "downvote");
_(-1, 0, a + "downvoted");

alert(string);

Answer 6

Game Maker Language, 276

p=real(keyboard_string())-1j="#"s=""z=" answer"w=" accept"x=" upvoted"+j;y=w+"ed"v=" question"u=" downvoted"if m=floor(p/15)s+=(m+z+y)+j;r=p-m*15if m=floor(r/10)s+=(m+z+x)r-=m*10if m=floor(r/5)s+=(m+v+x)r-=m*5n=floor(r/2)r-=n*2if m=r{n++;s+=(m+u+z)+j}s+=(n+y+z)show_message(s)

Answer 7

C# - 391

A bit long, and I haven't tested this thoroughly (much). :)

class R{void Main(string[] a){var r=int.Parse(a[0])-1;var a=new[]{15,10,5,2};var o=new List<string>();Func<int,string>y=z=>{var w="";if(z==15)w=" answer accepted";if(z==10)w=" answer upvotes";if(z==5)w=" question upvotes";if(z==2)w=" answer accepts";return w;};foreach(var x in a)if(r/x>0){o.Add(r/x+y(x));r-=(r/x)*x;}if(r==1)o.Add("1 question downvotes");Console.Write(string.Join(", ",o));

Un-golfed - NEW

class R
{
    void Main(string[] a)
    {
        var r = int.Parse("122")-1; // subtracts 1 from total rep
        var a = new[] {15,10,5,2};
        var o = new List<string>();
        
        Func<int,string> y = 
            z => 
                {
                    var w="";
                    if(z==15) w=" answer accepted";
                    if(z==10) w=" answer upvotes";
                    if(z==5) w=" question upvotes";
                    if(z==2) w=" answer accepts";
                    return w;
                };
        
        foreach(var x in a) {
            if (r/x>0) {
                o.Add(r/x+y(x));
                r-=(r/x)*x;
            }
        }
            
        if(r==1)
            o.Add("1 question downvotes");
            
        Console.Write(string.Join(", ",o));
    }
}

Un-golfed - OLD (409)

class R
{
    void Main(string[] a)
    {
        var r = int.Parse(a[0])-1; // subtracts 1 from total rep
        var v = new[] {" question"," answer"," downvotes"," upvotes"," accepts"," accepted"};
        var o = new List<string>();
        
        // Starts from 15, then checks all the lower values.
        if (r/15>0) {
            o.Add(r/15+v[1]+v[5]);
            r-=(r/15)*15; // automatic rounding down due to int
        }
        if(r/10>0) {
            o.Add(r/10+v[1]+v[3]);
            r-=(r/10)*10;
        }
        if(r/5>0) {
            o.Add(r/5+v[0]+v[3]);
            r-=(r/5)*5;
        }
        if(r/2>0) {
            o.Add(r/2+v[1]+v[4]);
            r-=(r/2)*2;
        }
        if(r==1) {
            o.Add("1"+v[0]+v[2]);
        }
        Console.Write(string.Join(", ",o));
    }
}

Test:

> prog.exe 120

7 answer accepted, 1 answer upvotes, 2 answer accepts 

Answer 8

Python - 213 207

p,k=__import__('itertools').combinations_with_replacement,int(input())
t,m,u=[5,10,-2,-1,15,2],[],iter(range(0,k))
while not m:m=list(filter(lambda v:k-1==sum(v),p(t,next(u))))
print(''.join(map(chr,m[0])))

Curse you long function names!

Example: (ignore the trailing newline)

$ echo "93" | python per.py | hexdump -C
00000000  0f 0f 0f 0f 0f 0f 02 0a                           |........|

$ echo "11" | python per.py | hexdump -C
00000000  0a 0a                                             |..|

Answer 9

C++, 276 (316 w/ includes)

#include <stdio.h>
#include <stdlib.h>
p(int&q,int*d){int r;char*s[]={"downvoted","accepted","question","answer","upvoted"};
if(r=(q&&q>=*d)){q-=(*d?*d:2);printf("%s %s\n",s[*(++d)],s[*(++d)]);}return r;}main(
int n,char**v){int q=atoi(v[1]);int d[]={-1,3,0,0,3,1,5,4,2,10,4,3,15,1,3};n=15;while
(p(q,d+n-3)||(n-=3));}

Compiles with GCC, with warnings. Example:

$ ./a.out 0
$ ./a.out 1
accepted answer
downvoted answer
$ ./a.out 2
accepted answer
$ ./a.out 5
question upvoted
$ ./a.out 10
answer upvoted
$ ./a.out 15
answer accepted
$ ./a.out 16
answer accepted
accepted answer
downvoted answer
$ ./a.out 17
answer accepted
accepted answer

Feel free to port this to a language that doesn't require type declarations and post it as your own.

Answer 10

JavaScript - 273 256 235

p=prompt(s=j="\n")-1;z=" answer",w=" accept",x=" upvoted"+j,y=w+"ed",v=" question",u=" downvoted";if(m=p/15|0)s+=m+z+y+j;r=p-m*15;if(m=r/10|0)s+=m+z+x;r-=m*10;if(m=r/5|0)s+=m+v+x;r-=m*5;n=r/2|0;if(m=r-=n*2)n++,s+=m+u+z+j;alert(s+n+y+z)

Combined calculation and output, and golfed further to a total of 287.

Edit: took out some variables for a few shorter.

Removed Math.Floor for |0 approach.

Moved some initialisation to the prompt() param, removed some brackets, alert with final string append.

Answer 11

Python3, 188B

n=input()+1
a=n//15
n%=15
A='answer '
print("%d %saccepted\n%d %supvoted\n%d question upvoted\n%d accept %s\n%d downvote %s\n%d %sdownvoted"%(a,A,n//10,A,n%10//5,n%5>2,A,n%5%2,A,n%5==0,A))

Usage: python3 score.py <ret> 11 <ret> where this script is saved as score.py.

Sample output:

$ python score.py
5543
369 answer accepted
0 answer upvoted
1 question upvoted
1 accept answer 
0 downvote answer 
0 answer downvoted