hyone

;; hyone's solution to Pascal's Triangle
;; https://4clojure.com/problem/97

(fn [n] (nth (iterate #(vec (map + (conj % 0) (cons 0 %))) '[1]) (dec n)))

hyone

;; hyone's solution to Symmetric Difference
;; https://4clojure.com/problem/88

#(cond
  (empty? %1) %2
  (empty? %2) %1
  :else (apply disj (apply conj %1 %2) (filter %1 %2)))

hyone

;; hyone's solution to Merge with a Function
;; https://4clojure.com/problem/69

(fn my-merge-with [f & maps]
  (reduce
    (fn [a b]
      (reduce
        (fn [x [k v]]
          (assoc x k (if (b k) (f v (b k)) v)))
        b a))

hyone

;; hyone's solution to Black Box Testing
;; https://4clojure.com/problem/65

(defn seq-type [coll]
  (let [base (empty coll)]
    (cond
      (= base {})  :map
      (= base #{}) :set
      (= base '()) (if (reversible? coll) :vector :list))))