rendezvous with cassidoo challenge: 23-09-04

min_subs.clj

(ns min-subs
  (:require [clojure.test :refer [deftest is]]))

(defn min-subs [nums k]
  (let [subarrays (partition k 1 nums)]
    (reduce (fn [min-array next-array]
              (let [[sum-a sum-b]
                    (map (partial apply +) [min-array next-array])]
                (if (< sum-a sum-b)
                  min-array
                  next-array)))
            (first subarrays)
            (rest subarrays))))

(deftest min-subs-test
  (is (= [4 8 9] (min-subs [1 3 20 4 8 9 11] 3)))
  (is (= [4 4] (min-subs [4 4 4 4 8] 2))))

I found this excellent solution that introduced me to the min-key function in clojure.core:

(defn min-subs [xs k]
  (->> xs
       (partition k 1)
       (apply min-key (fn [part] (apply + part)))))

The solution was found at: https://github.com/mebble/rendezvous-with-cassidoo/blob/main/2023-09-04.clj
min-key docs: https://clojuredocs.org/clojure.core/min-key