gdeer81

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; string s = "123456789"
;; int target = 100
;; how many combinations of +/- give you the target int?
;; + and - can be inserted at any index
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

;;;;;;helper functions;;;;;;
(defn str->vec
  "converts a string of consecutive numbers to a vector of individual numbers

gdeer81

;;;;;;;;;Given this yucky implementation:
(defn print-row [num]
   (loop [iter 0])
   (if (< iter num)
     (do (print "*")
         (recur (inc iter)))
    (println "")))

(defn print-a-triangle [num]
  (loop [iter 0]

gdeer81

(set! *unchecked-math* false)

(defn find-the-pairs [^long n]
  "takes an upper bound and returns all the pairs of numbers where
  (* x y) equals the sum of the entire collection without x and y
   (find-the-pairs 26) => [[15 21] [21 15]]
  "
  (let [^long coll-sum (/ (* n (inc n)) 2)]
    (for [^long i (range 1 (inc n)) ^long j (range 1 (inc n))
          :when (= (- coll-sum i j) (* i j))]

gdeer81

;;this works until you pass in ridiculously large numbers
;; the for loop lets me try all of the numbers in the collection with each other

(defn find-the-pairs [n]
  "takes an upper bound and returns all the pairs of numbers where 
  (* x y) equals the sum of the entire collection without x and y
   (find-the-pairs 26) => [[15 21] [21 15]]
  "
  (let [coll (take n (iterate inc 1))
        coll-sum (apply + coll)]

gdeer81

(def inc-coll (partial map inc))
;;#'user/inc-coll
(inc-coll [4 5 6])
;;(5 6 7)
(def inc-coll-coll (partial map inc-coll))
;;#'user/inc-coll-coll
(inc-coll-coll [[1] [2]])
;;((2) (3))
(inc-coll-coll [[1] 3])
;;IllegalArgumentException Don't know how to create ISeq from: java.lang.Long  clojure.lang.RT.seqFrom (RT.java:542)

gdeer81

;; Filtering

; product visible when no filter
(define [:app :visible-product/id ?e] :- [:not [_ :product-filter/range]]
                                         [:not [_ :product-filter/category]]
                                         [[?e :product/name]])

; product visible when filter active and price in range
(define [:app :visible-product/id ?e]
  :- [[_ :product-filter/range ?range]]

gdeer81

(ns spec-test.core
  (:require [clojure.spec :as s]))

(defn x-integer? [x]
  (if (integer? x)
    x
    (if (string? x)
      (try
        (Integer/parseInt x)
        (catch Exception e

gdeer81

*in*
*ns*
aget
amap
as->
aset
atom
bean
byte
case

gdeer81

;;compare the two approaches to solving the same problem

;;A child plays with a ball on the nth floor of a big building the height of which is known
;;(float parameter "h" in meters, h > 0) .
;;He lets out the ball. The ball rebounds for example to two-thirds
;;(float parameter "bounce", 0 < bounce < 1)
;;of its height.
;;His mother looks out of a window that is 1.5 meters from the ground
;;(float parameters window < h).
;;How many times will the mother see the ball either falling or bouncing in front of the window

gdeer81

 <!-- server passes in a collection of product maps -->
 <!-- controller now sends a collection of collections of product maps, specifically (partition-all 4 products) -->
 
  {% for product-partition in partitioned-products %}
    {% for product in product-partition %}
        <div class="col-sm-10 col-sm-offset-2">
          <div class="row">
            <div class="col-sm-3" style="height:250px;">
              <p>{{product.name}}</p>
                <p>Price ${{product.price}}</p>