cypok

import com.sun.net.httpserver.HttpExchange;
import com.sun.net.httpserver.HttpHandler;
import com.sun.net.httpserver.HttpServer;

import java.io.*;
import java.net.InetSocketAddress;
import java.nio.charset.StandardCharsets;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.*;

cypok

#!/usr/bin/env ruby
# encoding: utf-8

require 'date'

def bad_usage
  puts "Usage: ledger_graph <output.svg> month_expenses <limit> [<year> <month>]"
  puts "   or: ledger_graph <output.svg> last_assets <months>"
  exit
end

cypok

UPD: задачи и решения переехали:

• пост на habrahabr.ru на русском
• post at excelsiorjet.com/blog in English

cypok

import gettext

lang = gettext.translation("wtf")
_ = lang.gettext

print(_("Program started")) # prints translated message

def work_hard():
  print(_("Working hard")) # raises UnboundLocalError: local variable '_' referenced before assignment
  #

cypok

for f in "$@"
do
  if [ "`GetFileInfo -ae "$f"`" == "0" ]
  then
    SetFile -a E "$f"
  else
    SetFile -a e "$f"
  fi
done

cypok

import java.util.Iterator;
import java.util.NoSuchElementException;

final class Tree<T> {

    private final T elem;
    private final Tree<T> parent;

    private Tree(T elem, Tree<T> parent) {
        this.elem = elem;

cypok

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

typedef enum eChildKind {
    LEFT,
    RIGHT,
} ChildKind;

cypok

The problem was fixed in less than a day after publication of this page.

The problem

Speaker Deck uses nice OpenSans font. However some characters are rendered using other fonts, e.g. cyrillic characters.

So if you mix in description both latin and cyrillic characters it looks bad. Latin characters are rendered using [lite 300 OpenSans

cypok

public class Absents {
    public static void main(String args[]) {
        try { callClone(null); } catch (Throwable e) { System.out.println(e); }
        try { callToString(null); } catch (Throwable e) { System.out.println(e); }
    }


    static void callClone(Fail[] arr) {
        arr.clone();
    }

cypok

Original post at Coursera's proglang discussion forum is here.

After reviewing code of other students I formulated one very common problem: mixing tabs and spaces.

If student writes his code in editor which inserts tabs as is (as '\t' character) it is OK. However when student starts to add extra formatting with spaces (e.g. align if, then and else) his code becomes a problem. Look at the example with tab width 4 (tabs are shown as ->, spaces as spaces):