Quick Golf: The Gold Leader

Question

Challenge

Using data from the API here, output the names of the three countries with the most Olympic gold medals at the 2016 Rio Olympic Games (i.e. the first element of the returned list).

For example, at the time of posting (18:23 UTC+1, Monday, 15th August), the USA, the UK and China have the most gold medals, so the output would be:

United States
Great Britain
China

The country names must be separated by newlines and you may have a leading or trailing newlines.

Once the Olympics have finished, the program does not have to work as expected.

URL shorteners are disallowed but JSON parsing libraries are allowed.

This is code golf, so the shortest code in bytes wins.

^{I'm going to keep trying to get an Olympics themed challenge in here}

Leaderboard

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body{text-align:left!important}#answer-list,#language-list{padding:10px;width:290px;float:left}table thead{font-weight:700}table td{padding:5px}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script> <link rel="stylesheet" type="text/css" href="//cdn.sstatic.net/codegolf/all.css?v=83c949450c8b"> <div id="answer-list"> <h2>Leaderboard</h2> <table class="answer-list"> <thead> <tr><td></td><td>Author</td><td>Language</td><td>Size</td></tr></thead> <tbody id="answers"> </tbody> </table> </div><div id="language-list"> <h2>Winners by Language</h2> <table class="language-list"> <thead> <tr><td>Language</td><td>User</td><td>Score</td></tr></thead> <tbody id="languages"> </tbody> </table> </div><table style="display: none"> <tbody id="answer-template"> <tr><td>{{PLACE}}</td><td>{{NAME}}</td><td>{{LANGUAGE}}</td><td>{{SIZE}}</td><td><a href="{{LINK}}">Link</a></td></tr></tbody> </table> <table style="display: none"> <tbody id="language-template"> <tr><td>{{LANGUAGE}}</td><td>{{NAME}}</td><td>{{SIZE}}</td><td><a href="{{LINK}}">Link</a></td></tr></tbody> </table>

Answer 1

C (+sockets), 433 429 280 276 270 259 bytes

#define H"medalbot.com"
char**p,B[999],*b=B;main(f){connect(f=socket(2,1,getaddrinfo("www."H,"80",0,&p)),p[4],16);send(f,"GET http://"H"/api/v1/medals HTTP/1.1\r\nHost:"H"\r\n\r\n",69);read(f,b,998);for(f=3;f--;puts(p))b=strchr(p=strstr(++b,"_n")+9,34),*b=0;}

So it turns out that C isn't great at downloading resources from the internet and parsing them as JSON. Who knew?

This code is (naturally) super lax with error checking, so I guess if medalbot.com wanted to send malicious data they'd be able to trigger buffer overflows, etc. Also the latest code expects certain values for the constants (e.g. AF_INET = 2) which will probably be the case everywhere, but it's not guaranteed.

Here's the original code which isn't so fragile (but still isn't very robust or safe):

#include<netdb.h>
#define H"medalbot.com"
char*b,*B,d[999];struct addrinfo*p,h;main(f){h.ai_socktype=SOCK_STREAM;getaddrinfo("www."H,"80",&h,&p);f=socket(p->ai_family,p->ai_socktype,p->ai_protocol);connect(f,p->ai_addr,p->ai_addrlen);send(f,"GET http://"H"/api/v1/medals HTTP/1.1\r\nHost: "H":80\r\nConnection: close\r\n\r\n",92,0);recv(f,d,998,0);for(f=0,b=d;f<3;++f)B=strstr(b,"_n")+9,b=strchr(B,'}'),*strchr(B,'"')=0,puts(B);}

Breakdown:

                            // No imports needed whatsoever!
#define H"medalbot.com"     // Re-use the host in multiple places
char**p,                    // This is actually a "struct addrinfo*"
    B[999],                 // The download buffer (global to init with 0)
    *b=B;                   // A mutable pointer to the buffer

main(f){
    // Hope for the best: try the first suggested address with no fallback:
    // (medalbot.com runs on Heroku which has dynamic IPs, so we must look up the
    // IP each time using getaddrinfo)
    f=socket(2,1,getaddrinfo("www."H,"80",0,&p));
                            // 2 = AF_INET
                            // 1 = SOCK_STREAM
                            //     (may not match getaddrinfo, but works anyway)
                            // 0 = IP protocol (getaddrinfo returns 0 on success)
    connect(f,p[4],16);     // struct addrinfo contains a "struct sockaddr" pointer
                            // which is aligned at 32 bytes (4*8)

    // Send the HTTP request (not quite standard, but works. 69 bytes long)
    send(f,"GET http://"H"/api/v1/medals HTTP/1.1\r\nHost:"H"\r\n\r\n",69);
    // (omit flags arg in send and hope 0 will be assumed)

    read(f,b,998);          // Get first 998 bytes of response; same as recv(...,0)

    // Loop through the top 3 & print country names:
    // (p is re-used as a char* now)
    for(f=3;f--;puts(p))        // Loop and print:
        p=strstr(++b,"_n")+9,   //  Find "country_name": "
        b=strchr(p,34),         //  Jump to closing "
        *b=0;                   //  Set the closing " to \0
}

This isn't very nice for the server since we don't send Connection: close\r\n as part of the HTTP request. It also omits the Accept header since medalbot.com doesn't seem to be using compression in any case, and misses the space after Host: (again, the server seems to be OK with this). It doesn't seem as though anything else can be removed though.

---

Once the olympics end, the most likely behaviour for this program is to segfault trying to read memory location 9. Unless an evil hacker takes over the domain, in which case the most likely behaviour is for it to set some byte to 0 in the address info structs, which probably isn't too dangerous actually. But who can tell with these evil hackers?

Answer 2

bash + w3m + grep + cut, 65 59 58 54 bytes

w3m medalbot.com/api/v1/medals|grep -m3 m|cut -d\" -f4

• 6 bytes less thanks to @Joe's suggestions.
• 1 byte less thanks to @YOU.
• 4 bytes less thanks to @manatwork's suggestion that the medalbot API seems to work without www. subdomain too.

Answer 3

PowerShell v4+, 88 69 bytes

(ConvertFrom-Json(iwr medalbot.com/api/v1/medals))[0..2].country_name

Uses iwr (the alias for Invoke-WebRequest) to grab the API. We feed that as the input parameter to the ConvertFrom-Json built-in that pulls the JSON text into a custom object array. We encapsulate that object array in parens, take the first three elements [0..2], and take the .country_name of each thereof.

Requires at least v4+ for the multiple-object-properties, else we'd need to use something like |Select "country_name" instead. Requires at least v3+ for the ConvertFrom-Json built-in.

PS C:\Tools\Scripts\golfing> .\olympics-gold-leader.ps1
United States
Great Britain
China

Answer 4

R, 98, 112, 108 bytes

golfed 4 thanks to @miff

a=jsonlite::fromJSON(readLines("http://www.medalbot.com/api/v1/medals"))
cat(a$c[order(-a$g)[1:3]],sep="\n")

First line imports data using a JSON library. Second line grabs the relevant country names. It sorts the countries by gold medals in increasing order, reverses the indices, and takes the first 3, printing them.

Answer 5

JavaScript (ES6), 122 Bytes

fetch`http://www.medalbot.com/api/v1/medals`.then(a=>a.json()).then(b=>alert(b.slice(0,3).map(c=>c.country_name).join`\n`))

Due to a browser safety issue, this code must be run on medalbot.com. It does not however take advantage of that and could potentially be run elsewhere. Also note that I inserted the \n character, but am only counting is as one, because I could replace it with one

Node.js (ES6), 173 Bytes

require("http").get("http://www.medalbot.com/api/v1/medals",s=>s.on("data",d=>t+=d,t="").on("end",q=>console.log(JSON.parse(t).slice(0,3).map(a=>a.country_name).join`\n`)))

This would have been so much shorter if the API returned the data all in one stretch, but since it returns in two sections, I must concatenate the parts and combine them, and then parse them.

Node.js (ES6) + Request, 138 Bytes

require("request")("http://www.medalbot.com/api/v1/medals",(e,r,b)=>console.log(JSON.parse(b).slice(0,3).map(a=>a.country_name).join`\n`))

Better, but still not as good as the browser version. Thanks fetch API! Request is a popular HTTP client library used to simplify requests, and you can see that take effect here.

Answer 6

bash + w3m + jq, 83 59 bytes

w3m medalbot.com/api/v1/medals|jq -r '.[:3][].country_name'

Thanks to Jordan for three bytes.

Thanks to YOU for 24 more bytes! Turns out the data is sorted. Wow. :D

Answer 7

Java 8, 261 258 bytes

This uses a lambda to save a couple bytes and the net library to get the webpage. Other than that is just Java.

()->{try{for(int i=0;i<3;System.out.println(new java.util.Scanner(new java.net.URL("http://www.medalbot.com/api/v1/medals").openConnection().getInputStream()).useDelimiter("\\A").next().split("\n")[i++*9+3].replaceAll(".* \"|\",","")));}catch(Exception e){}}

Here is my (old) POJO for testing (and golfing):

class QuickGolf {
  static void f(h x){x.g();}
  static interface h{ void g(); }
  static void main(String[] args){
    f(
      ()->{try{for(int i=0;i<3;i++){System.out.println(new java.util.Scanner(new java.net.URL("http://www.medalbot.com/api/v1/medals").openConnection().getInputStream()).useDelimiter("\\A").next().split("\n")[i*9+3].substring(21).replace("\",",""));}}catch(Exception e){}}
    );
  }
}

---

Update

• -3 [16-08-17] Move print statement into for loop
• -5 [16-08-16] Improved regex replace
• -9 [16-08-16] Removed java.net import

Answer 8

MATL, 67 bytes

'http://www.medalbot.com/api/v1/medals'Xi'(?<="c.+e": ")[^"]+'XX3:)

This doesn't work online because function Xi (urlread) is disallowed.

Example run:

>> matl
 > 'http://www.medalbot.com/api/v1/medals'Xi'(?<="c.+e": ")[^"]+'XX3:)
 > 
United States
Great Britain
China

Explanation

This reads the contents as a string and then applies the regex '(?<="c.+e": ")[^"]+' to extract country names. The regex uses look-behind with "c.+e" instead of "country_name" to reduce code length.

'http://www.medalbot.com/api/v1/medals'   % Push string representing the URL
Xi                                        % Read URL contents as a string
'(?<="c.+e": ")[^"]+'                     % String for regex matching
XX                                        % Apply regex
3:)                                       % Get first 3 results

Answer 9

Python 3, 202, 164 bytes.

Python 3 does not do short url/json handling. :/
Didn't realize the API already sorts by gold count

from urllib.request import*
import json
print('\n'.join(x['country_name']for x in json.loads(urlopen('http://www.medalbot.com/api/v1/medals').read().decode())[:3]))

Answer 10

Python 2, 120 113 bytes

from urllib import*
for x in list(urlopen("http://www.medalbot.com/api/v1/medals"))[3:26:9]:
    print x[21:-4]

Thanks @Nick T and @Value Ink

Answer 11

JavaScript + jQuery, 114 100 bytes

$.get("www.medalbot.com/api/v1/medals",a=>alert(a[0][c='country_name']+'\n'+a[1][c]+'\n'+a[2][c]))

For the reason of Cross Origin Requests, this must be run from the medalbot.com domain (with jQuery).

History

• -14 bytes thanks to @YetiCGN
• -2 bytes thanks to Yay295

Answer 12

Ruby, 97 79 + -rnet/http (11) = 90 bytes

Uses a modification of the regex pattern from Luis Mendo's MATL answer, further optimized by @Jordan, since Ruby doesn't support quantifiers in lookbehinds.

-18 bytes from @Jordan.

puts Net::HTTP.get("www.medalbot.com","/api/v1/medals").scan(/"c.+"(.+)"/)[0,3]

Answer 13

PowerShell, 60

(iwr medalbot.com/api/v1/medals|convertfrom-json)[0..2]|% c*

Same basic idea as TimmyD (didn't see their answer before I posted), but quite a bit shorter :-)

Answer 14

Mathematica 96 66 bytes

@alephalpha found a way to work directly from the file (without saving it), thereby saving 30 bytes!

Import["http://www.medalbot.com/api/v1/medals","RawJSON"][[;;3,2]]

Import imports the file as a Raw JSON file. [[;;3,2]]takes rows 1-3, second entry (country name).

Answer 15

PHP, 205 139 124 116 111 109 bytes

I just wanted to use the new spaceship operator for PHP 7 once (EDIT: It's superfluous, as sorting isn't required):

<?$d=json_decode(file_get_contents('http://www.medalbot.com/api/v1/medals'),1);usort($d,function($a,$b){$g='gold_count';return$b[$g]<=>$a[$g];});$c='country_name';foreach([0,1,2]as$i){echo$d[$i][$c]."\n";}

If we omit the unneccesary sorting step and assume the API delivers the data already sorted by gold_count descending (as it would seem), we can shorten this further:

while($i<3)echo json_decode(file_get_contents('http://medalbot.com/api/v1/medals'))[+$i++]->country_name."
";

Note: The line break within the string is intentional to save a byte from \n

History

• Ommitted some quotes and braces that will throw notice's, removed the $c variable for country_name index. Thanks to @manatwork for these tipps to save even more characters.
• Thanks to @jeroen for pointing out the shorter while loop, also switched to object access to go from 124 to 116
• Saved 5 more bytes by calling the API within the loop. Granted, it takes longer and clobbers the API, but it's Code Golf. Needs PHP 5.5 to work because of array dereferencing.
• Saved 2 more bytes by removing the short open tag, as per this meta answer

Answer 16

BASH + w3m + core utils, 70 bytes

w3m www.medalbot.com/api/v1/medals|grep -m3 tr|cut -f6- -d\ |tr -d \",

Looks like the output comes sorted already. Just need to throw out all of the extra text.

Answer 17

CJam (57 bytes)

"http://www.medalbot.com/api/v1/medals"gN/3>9%3<{'"/3=N}%

Online demo not available because it fetches content from the web. This cheats by not actually parsing JSON, but assuming that the structure won't change. (But then so do most of the existing answers, in different ways).

Answer 18

Python 2, 117 bytes

from requests import *
for x in get('http://www.medalbot.com/api/v1/medals').json()[:3]:
    print(x['country_name'])

Answer 19

Clojure, 122 bytes

(fn[](mapv #(println(%"country_name"))(take 3(read-string(.replace(slurp"http://www.medalbot.com/api/v1/medals")":""")))))

No JSON library used :). Reads string from the URL, replaces colons with empty string and evals the string which results into Clojure map. Takes first 3 elements and maps eagerly function which prints country_name property of each elements.

Answer 20

Java 8 386 384 459 bytes

2 bytes saved from @Easterly Irk

My first code golf submission so I'm sure there's a way to save plenty of bytes, but oh well :)

It uses Gson to read the JSON

Requires:

import java.util.*;
import java.io.*;

Golfed code:

void p()throws Exception{List<A> a=new com.google.gson.Gson().fromJson(new InputStreamReader((InputStream)((new java.net.URL("http://www.medalbot.com/api/v1/medals").openConnection())).getContent()),new com.google.gson.reflect.TypeToken<List<A>>(){}.getType());a.sort((b,c)->c.gold_count.compareTo(b.gold_count));for(int i=0;i<3;)System.out.println(a.get(i++).country_name);}class A{String country_name;Integer gold_count;}

Ungolfed Code:

void p() throws Exception {
    List<A> a = new com.google.gson.Gson().fromJson(new InputStreamReader((InputStream)((new java.net.URL("http://www.medalbot.com/api/v1/medals").openConnection())).getContent()),new com.google.gson.reflect.TypeToken<List<A>>(){}.getType());
    a.sort((b, c) -> c.gold_count.compareTo(b.gold_count));
    for(int i=0; i<3;)
        System.out.println(a.get(i++).country_name);
}

class A {
    String country_name;
    Integer gold_count;
}

Answer 21

R, 97 95 bytes

t=rjson::fromJSON(f="http://www.medalbot.com/api/v1/medals")
for(i in 1:3)cat(t[[c(i,2)]],"\n")

Little improvement over user5957401's answer, no sorting required, and shorter library name. Also my first attempt at golfing ;)

Answer 22

Kotlin (Script), 125 121 119 bytes

java.net.URL("http://medalbot.com/api/v1/medals").readText().lines().filter{'m' in it}.take(3).map{println(it.split('"')[3])}

Runnable with kotlinc -script <filename> or through IDEA as *.kts file.

now, if we make a VERY big assumption about the format, including numbers of lines, we can trim it to:

java.net.URL("http://medalbot.com/api/v1/medals").readText().lines().slice(setOf(3,12,21)).map{println(it.split('"')[3])}

or even

java.net.URL("http://medalbot.com/api/v1/medals").readText().lines().slice(3..21 step 9).map{println(it.split('"')[3])}

Thanks to folks at Kotlin slack team for helping me trim a couple dozens of bytes!

Answer 23

Javascript 167 bytes

x=new XMLHttpRequest();x.open("GET","http://www.medalbot.com/api/v1/medals",false);x.send()
i=-3;while(i++)console.log(JSON.parse(x.responseText)[i+2]["country_name"])