thisiswei

(define fib3 
  (letrec([memo null] ; list of pairs (arg . result)
          [f (lambda (x)
               (let ([ans (assoc x memo)])
                (if ans 
                  (cdr ans)
                  (let ([new-ans (if (or (= x 1) (= x 2))
                                   1
                                   (+ (f (- x 1))
                                      (f (- x 2))))])

thisiswei

(define (ps1 x)
  (if (equal? 0 x)
    0
    (if (or (equal? 0 (modulo x 3)) (equal? 0 (modulo x 5)))
      (+ x (ps1 (- x 1)))
      (ps1 (- x 1)))))

(ps1 999)

thisiswei

"""Embedded in this block of text is the password for level 2.
  The password is the longest substring that is the same in reverse.

  As an example, if the input was "I like racecars that go fast"
  the password would be "racecar".
  challenge from http://challenge.greplin.com/
  """

text = """FourscoreandsevenyearsagoourfaathersbroughtforthonthiscontainentanewnationconceivedinzLibertyanddedicatedtothepropositionthatallmenarecreatedequalNowweareengagedinagreahtcivilwartestingwhetherthatnaptionoranynartionsoconceivedandsodedicatedcanlongendureWeareqmetonagreatbattlefiemldoftzhatwarWehavecometodedicpateaportionofthatfieldasafinalrestingplaceforthosewhoheregavetheirlivesthatthatnationmightliveItisaltogetherfangandproperthatweshoulddothisButinalargersensewecannotdedicatewecannotconsecratewecannothallowthisgroundThebravelmenlivinganddeadwhostruggledherehaveconsecrateditfaraboveourpoorponwertoaddordetractTgheworldadswfilllittlenotlenorlongrememberwhatwesayherebutitcanneverforgetwhattheydidhereItisforusthelivingra

thisiswei

"""
1) Win: If you have two in a row, play the third to get three in a row.  
2) Block: If the opponent has two in a row, play the third to block them.  
3) Fork: Create an opportunity where you can win in two ways.
4) Block Opponent's Fork: 
5) Center: Play the center.  
6) Opposite Corner: If the opponent is in the corner, play the opposite corner.  
7) Empty Corner: Play an empty corner.  
8) Empty Side: Play an empty side.
"""

thisiswei

(define (expand-row p)
  (cons (car p) (expand-row-rest p)))

(define (expand-row-rest p)
  (if (null? (cdr p)) (list 1)
      (cons (+ (car p) (cadr p)) 
            (expand-row-rest (cdr p)))))

(define (pascals-row n)
  (if (= n 0) (list 1)

thisiswei

(define (getFinalAmount initial res)
  (define (helper total bet n)
    (cond [(or (> (+ 1 n) (string-length res)) (> bet total)) total]
          [(eq? (string-ref res n) #\L) (helper (- total bet) (* 2 bet) (+ n 1))]
          [#t (helper (+ amount total) 1 (+ n 1))]))
  (helper initial 1 0))

thisiswei

def getFinalAmount(initial, res):
 
    def helper(total, bet, n): 
        return (total if n > len(res) - 1 or bet > total  else
                helper(total-bet, bet*2, n+1) if res[n] == 'L' else 
                helper(total+bet, 1, n+1))
 
    return helper(initial, 1, 0)

thisiswei

getFinal initial res = helper initial 1 0
    where helper total bet n = if n > (length res) - 1 || bet > total.
                               then total
                               else if res !! n == 'L'.
                               then helper (total-bet) (bet*2) (n+1)
                               else helper (total+bet) 1 (n+1)

thisiswei

fun getFinal init res =   
    let
        fun helper total bet n =
            case n+1 > size res of
                 true => total
               | _ => if String.sub (res, n) = #"L"
                      then helper (total-bet) (bet*2) (n+1)
                      else helper (total+bet) 1 (n+1) 
    in
        helper init 1 0

thisiswei

def dvr_remote(s, width): 
    x =  'ABCDEFGHIJKLMNOPQRSTUVWXYZ_'
    rows = [x[i:i+width] for i in range(0, 27, width)]
    s = 'A' + s.replace(' ', '_')
    DIC = dict((char, (i, pos)) 
                for i in range(len(rows)) 
                for (pos, char) in enumerate(rows[i]))

    def helper(current, next):
        row1, col1 =  DIC[current]