rendezvous with cassidoo challenge: 23-11-15

do_tasks.clj

(ns do-tasks
  (:require [clojure.test :refer [deftest is]]))

(defn do-tasks [tasks time-to-work]
  (let [time-remaining  (atom time-to-work)
        sorted-tasks    (sort-by :duration tasks)
        completed-tasks (set
                          (reduce (fn [completed-tasks next-task]
                                     (if (>= @time-remaining (:duration next-task))
                                       (do
                                         (swap! time-remaining - (:duration next-task))
                                         (conj completed-tasks next-task))                                                        
                                       (reduced completed-tasks)))
                                  []
                                  sorted-tasks))]
    (for [task tasks
          :when (contains? completed-tasks task)]
      (:name task))))

(deftest do-tasks-test
  (let [tasks [{:name "Task 1" :duration 4}
               {:name "Task 2" :duration 2}
               {:name "Task 3" :duration 7}
               {:name "Task 4" :duration 5}
               {:name "Task 5" :duration 1}
               {:name "Task 6" :duration 3}]]

    (is (= ["Task 2" "Task 5" "Task 6"] (do-tasks tasks 6)))
    (is (= ["Task 2" "Task 5"] (do-tasks tasks 4)))))