hroi

; Problem 11
;
; What is the greatest product of four adjacent numbers in any direction (up,
; down, left, right, or diagonally) in the 2020 grid?

(def grid20 [[ 8  2 22 97 38 15  0 40  0 75  4  5  7 78 52 12 50 77 91  8]
	     [49 49 99 40 17 81 18 57 60 87 17 40 98 43 69 48  4 56 62  0]
	     [81 49 31 73 55 79 14 29 93 71 40 67 53 88 30  3 49 13 36 65]
	     [52 70 95 23  4 60 11 42 69 24 68 56  1 32 56 71 37  2 36 91]
	     [22 31 16 71 51 67 63 89 41 92 36 54 22 40 40 28 66 33 13 80]

hroi

user> (time (reduce + (loop [foo 0 bar '()]
	 (if (= foo 1000000)
	     bar
	     (recur (inc foo) (cons foo bar))))))
"Elapsed time: 912.220229 msecs"
499999500000
user> (time (reduce + (loop [foo 0 bar (transient [])]
	 (if (= foo 1000000)
	     (persistent! bar)
	     (recur (inc foo) (conj! bar foo))))))

hroi

; Problem 12
; 
; What is the value of the first triangle number to have over five hundred divisors?
; 

(def natnums (iterate inc 1))
(def trinums (lazy-cat [(first natnums)] (map + trinums (rest natnums))))

(defn divcount [n]
  (* 2 (count

hroi

; Problem 13
; Work out the first ten digits of the sum of the following one-hundred 50-digit numbers.
;

(def answer 
     (let [numbers 
	   [37107287533902102798797998220837590246510135740250
	    46376937677490009712648124896970078050417018260538 
	    74324986199524741059474233309513058123726617309629
	    91942213363574161572522430563301811072406154908250

hroi

; Problem 14
;
; The following iterative sequence is defined for the set of positive integers:
;
; n -> n/2 (n is even)
; n -> 3n + 1 (n is odd)
;
; Using the rule above and starting with 13, we generate the following sequence:
;
; 13  40  20  10  5  16  8  4  2  1

hroi

; Problem 15
; Starting in the top left corner of a 22 grid, there are 6
; routes (without backtracking) to the bottom right corner.
; 
; How many routes are there through a 2020 grid?
; 

(def facts (lazy-cat [1] (map * facts (rest natnums))))

(defn solve [gridsize]

hroi

; Problem 17
;
; If the numbers 1 to 5 are written out in words: one, two, three, four, five, then there
; are 3 + 3 + 5 + 4 + 4 = 19 letters used in total.
;
; If all the numbers from 1 to 1000 (one thousand) inclusive were written out in words, how
; many letters would be used?

(defn say-number [n]
  (cond

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; Problem 19
; How many Sundays fell on the first of the month during the twentieth
; century (1 Jan 1901 to 31 Dec 2000)?

(count
 (for [year (range 1 101) month (range 0 12)
       :let [day (.getDay (doto (java.util.Date.) (.setYear year)
				(.setMonth month) (.setDate 1) (.getDay)))]
       :when (= day 0)]
   [year, month]))

hroi

; Problem 18
; By starting at the top of the triangle below and moving to adjacent
; numbers on the row below, the maximum total from top to bottom is 23.
; 
; 3
; 7 4
; 2 4 6
; 8 5 9 3
;
; That is, 3 + 7 + 4 + 9 = 23.

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(ns vm-clj
  (:import 
   (com.vmware.vim25.mo ServiceInstance
			InventoryNavigator)))

(def *defaults* {:url  (java.net.URL. "https://vcenter.example.com/sdk")
		 :username "joe"
		 :password "random"})

(defn get-service-instance [url username password]