pyrocat101

import select
import socket
import pycares


class CAresError(socket.error):
    def __init__(self, errno, strerror):
        super(CAresError, self).__init__(errno, strerror)

pyrocat101

x = {-
#if 0
0 + """".to_i => 0}
print `cat flag`
__END__
""".find('x')}
import os
p = os.system;{
#endif
1};

pyrocat101

type maybe = True of string
           | Maybe
           | False

type regex = Alt of regex * regex * maybe array
           | Then of regex * regex * maybe array
           | Star of regex * maybe array
           | Char of char

let make_memo () = Array.make 101 Maybe

pyrocat101

Simplify[RSolve[{a[n] == (B + 1) a[n - 1] - a[n - 2], a[0] == 0, a[1] == B}, a[n], n]]
Block[{B = 2}, Simplify[Table[a[n] /. First[%], {n, 10}]]]

pyrocat101

from collections import deque

class SyntaxError(Exception):
    pass

class RegexParser(object):
    """
    Alt ::= Concat ('|' Alt)*
          | Concat
    Concat ::= Star Star*

pyrocat101

(defn syntax-error []
  (throw (ex-info "Syntax Error" {})))
 
(declare alt then star prime)
 
(defn expect [s c]
  (if (not= (first s) c)
    (syntax-error)
    (rest s)))

pyrocat101

# get content in <td>...</td>
sed -n 's/<td>\(.*\)<\/td>/\1/gip' | \
# remove empty lines
grep -v "^\s*$" | \
# remove odd lines
sed -n '1~2!p' | \
# remove <u> tags
sed 's/<u>\(.*\)<\/u>/\1/gi' | \
# convert apostrophe (` -> ')
sed "s/\`/'/g" | \

pyrocat101

pad(W1, W2, X, Y) :-
  length(W1, L1),
  length(W2, L2),
  padZero(W1, W2, L1, L2, X, Y).

padZero(W1, W2, L, L, [0|W1], [0|W2]).
padZero(W1, W2, L1, L2, X, Y) :- L1 #> L2, pad(W1, [0|W2], X, Y).
padZero(W1, W2, L1, L2, X, Y) :- L1 #< L2, padZero(W2, W1, L2, L1, Y, X).

stripZero([], []).

pyrocat101

class TRIE(object):
    """
    >>> "foo" in TRIE(["foo", "bar"])
    True
    >>> "fo." in TRIE(["foo", "bar"])
    True
    >>> "f.o" in TRIE(["foo", "bar"])
    True
    >>> ".oo" in TRIE(["foo", "bar"])
    True

pyrocat101

;;
;; NS CHEATSHEET
;;
;; * :require makes functions available with a namespace prefix.
;;
;; * :use makes functions available without a namespace prefix
;;   (i.e., refers functions to the current namespace).
;;
;; * :import refers Java classes to the current namespace.
;;