请问您所见过的最棒的一段代码是什么？

Question

import re, collections
def words(text): return re.findall('[a-z]+', text.lower()) 
def train(features):
    model = collections.defaultdict(lambda: 1)
    for f in features:
        model[f] += 1
    return model
NWORDS = train(words(file('big.txt').read()))
alphabet = 'abcdefghijklmnopqrstuvwxyz'
def edits1(word):
   splits     = [(word[:i], word[i:]) for i in range(len(word) + 1)]
   deletes    = [a + b[1:] for a, b in splits if b]
   transposes = [a + b[1] + b[0] + b[2:] for a, b in splits if len(b)>1]
   replaces   = [a + c + b[1:] for a, b in splits for c in alphabet if b]
   inserts    = [a + c + b     for a, b in splits for c in alphabet]
   return set(deletes + transposes + replaces + inserts)
def known_edits2(word):
    return set(e2 for e1 in edits1(word) for e2 in edits1(e1) if e2 in NWORDS)
def known(words): return set(w for w in words if w in NWORDS)
def correct(word):
    candidates = known([word]) or known(edits1(word)) or known_edits2(word) or [word]
    return max(candidates, key=NWORDS.get)
;

Peter Norvig的Spelling Corrector

Answer 1

最神奇的代码莫过于 Quake III 中不可思议的求解平方根实现方法，尤其是神奇的常量0x5f3759df

float Q_rsqrt( float number )
{
    long i;
    float x2, y;
    const float threehalfs = 1.5F;

    x2 = number * 0.5F;
    y  = number;
    i  = * ( long * ) &y;  // evil floating point bit level hacking
    i  = 0x5f3759df - ( i >> 1 ); // what the fuck?
    y  = * ( float * ) &i;
    y  = y * ( threehalfs - ( x2 * y * y ) ); // 1st iteration
    // y  = y * ( threehalfs - ( x2 * y * y ) ); // 2nd iteration, this can be removed

    #ifndef Q3_VM
    #ifdef __linux__
        assert( !isnan(y) ); // bk010122 - FPE?
    #endif
    #endif
    return y;
}

还有这句比较好玩的：

rm -rf /usr /lib/nvidia-current/xorg/xorg

源自 https://github.com/MrMEEE/bumblebee/c...

Answer 2

#include<stdio.h>
int main()
{
   printf("hello world\n");
   return 0;
}

Answer 3

滚动的地球仪

http://jsfiddle.net/justjavac/KbetG/

Answer 4

try
{
    if(you.believe(it)  || !you.believe(it) ){
        I.believe(it); 
    }
}catch(Exception ex){
    throw new Exception ("It's a miracle!");
}finally{
   it.justHappened();
}

Answer 5

print“hello world”
print（“hello world”）
fmt.printf(“hello world”)
printf("hello world")
System.out.print("hello world")
document.write("hello world")
echo"hello world"
alert('Hello, World.');

hello world 我们学习的第一句语言 无论何种方式
无疑是最棒的。。

Answer 6

好吧，应该是这段，2011最佳代码Scala版

def believe(x: Any) = x match {
  case b: Boolean => "I believe."
  case _ => "It's miracle!"
}

Answer 7

看这个 国际C语言混乱代码大赛
https://zh.wikipedia.org/wiki/%E5%9B%...

Answer 8

10 PRINT "BASIC"
20 END

真的启蒙

Answer 9

很多，我觉得不需要文档和注释扫一眼就能看懂的代码都是很棒的代码。

Answer 10

qsort [] = []
qsort (x:xs) = qsort [a|a<-xs, a<x] ++ [x] ++ qsort [a|a<-xs, a>=x]

Answer 11

自己写的

lazy val fibs: Stream[Int] = 1 #:: 1 #:: (fibs zip fibs.tail).map(x => x._1 + x._2)

用Haskell更漂亮

Answer 12

fun append ([],ys) =ys
  | append (x::xs',ys) = x ::append (xs',ys)

Answer 13

hello world

Answer 14

推荐一个java的one-liner，实现读取流里的字符

String text = new Scanner( source ).useDelimiter("\\A").next();

这里给上关于one-liner读取流内容的博客地址，有兴趣大家可以看看

Answer 15

rm -rf /usr/ foo/bar

Answer 16

= =这种问题，不应该出现在知乎么？为啥在segmentdefault。。。。。