biesnecker

#!/usr/bin/env ruby

require 'flickraw'

FlickRaw.api_key = "YOUR FLICKR API KEY"
FlickRaw.shared_secret = "YOUR FLICKR SHARED SECRET"

ARGV[0] ||= "kittens"

search_query = ARGV[0]

biesnecker

(server/add-middleware 
  friend/authenticate
  { :credential-fn (partial creds/bcrypt-credential-fn users)
    :workflows [(workflows/interactive-form)]
    :login-uri "/login"
    :unauthorized-redirect-uri "/login"
    :default-landing-uri "/" })

(pre-route [:any "/app/*"] { :as req } (let [id (friend/identity req)]
  (when-not (friend/authorized? [::user] id) (friend/throw-unauthorized id {}))))

biesnecker

(defn bell 
  "Returns the nth Bell number"
  [n]
  (cond
    (= n 0) 1
    (= n 1) 1
    :else (reduce + (map #(abs (stirling-2 n %)) (range 0 (inc n))))))

biesnecker

(defn- stirling-loop-internal
  [^long n ^long k compfunc]
  { :pre [(<= k n)] }
  (let [workitems (for [n' (range 1 (inc n)) k' (range 0 (inc (- n k))) 
    :when (and (>= (- n' k') 0) (>= k (- n' k')))] [n' (- n' k')])]
    (loop [current (first workitems) items (rest workitems) results {}]
      (cond
        (= current [n k]) ((compfunc current results) current)
        (= (current 0) (current 1)) 
          (recur (first items) (rest items) 

biesnecker

(defn natural? 
  "Returns true if n is a natural number (greater than zero, and with no 
  fractional component), else false."
  [n] 
  (and (> n 0) (zero? (rem n 1))))

(defn nth-sgonal  
  "For a given s-gonal number P(s,n) = x, returns n (n is a natural number if
  x is a term of the given s-gonal sequence)."
  ^double [^long x ^long s]

biesnecker

(defn palindrome? [n] (let [numseq (seq (str n))] (= (reverse numseq) numseq)))

(defn euler-4 []
  (apply max 
    (for [x (range 999 900 -1) y (range x 900 -1) 
      :when (palindrome? (* x y))] 
      (* x y))))

biesnecker

(defn prog-sum 
  "Calculates the sum of an arithmetic progression"
  ([n a] (prog-sum n a a)) 
  ([n a d] (/ (* n (+ (* 2 a) (* (dec n) d))) 2)))

(defn euler-1 [n f1 f2]
  (let [
    b (dec n)
    d1 (quot b f1)
    d2 (quot b f2)

biesnecker

#(some {[:o :o :o] :o [:x :x :x] :x} 
        (partition 3 
          (map 
          (vec (flatten %))
           [0 1 2 3 4 5 6 7 8
            0 3 6 1 4 7 2 5 8 
            0 4 8 2 4 6])))

biesnecker

;; by inecas (http://www.4clojure.com/user/inecas)
(fn [c]
  (set (map set 
    (filter #(< 1 (count %)) 
      (vals (group-by sort c))))))

biesnecker

(def charvals (apply vector "ABCDEFGHJKMNPQRSTUVWXYZ23456789")) ; some characters weren't allowed in the codes
(defn rand-char [] (charvals (rand-int (count charvals))))

(apply str (take 10 (repeatedly rand-char)))