Find minimal result from applying all permutations of operations to all permutations of numbers

perm.clj

;; Find minimal result from applying all permutations of operations to all permutations of numbers

(defn remove-first [pred s]
  (lazy-seq
    (when-let [[x & xs] (seq s)]
     (cond (pred x) xs
           :else (cons x (remove-first pred xs))))))

(defn permutations [s]
  (lazy-seq
    (if (next s)
     (for [head s
           tail (permutations (remove-first #{head} s))]
       (cons head tail))
     [s])))


(defn find-min [coll ops]
  (for [[a b c] (permutations coll)
       [op1 op2] (permutations ops)]
   {:result ((eval op2) ((eval op1) a b) c)
    :nums   [a b c]
    :ops    [op1 op2]}))


(def v [2 3 4])
(def ops '(* + -))

(sort-by :result (find-min v ops))
;; =>
;;({:result -6, :nums [2 4 3], :ops [- *]}
;; {:result -4, :nums [2 3 4], :ops [- *]}
;; {:result -2, :nums [3 4 2], :ops [- *]}
;; {:result 1, :nums [2 3 4], :ops [+ -]}
;; {:result 1, :nums [2 4 3], :ops [- +]}
;; {:result 1, :nums [3 2 4], :ops [+ -]}
;; {:result 1, :nums [3 4 2], :ops [- +]}
;; {:result 2, :nums [2 3 4], :ops [* -]}
;; {:result 2, :nums [3 2 4], :ops [* -]}
;; {:result 2, :nums [4 3 2], :ops [- *]}
;; {:result 3, :nums [2 3 4], :ops [- +]}
;; {:result 3, :nums [2 4 3], :ops [+ -]}
;; {:result 3, :nums [4 2 3], :ops [+ -]}
;; {:result 3, :nums [4 3 2], :ops [- +]}
;; {:result 4, :nums [3 2 4], :ops [- *]}
;; {:result 5, :nums [2 4 3], :ops [* -]}
;; {:result 5, :nums [3 2 4], :ops [- +]}
;; {:result 5, :nums [3 4 2], :ops [+ -]}
;; {:result 5, :nums [4 2 3], :ops [* -]}
;; {:result 5, :nums [4 2 3], :ops [- +]}
;; {:result 5, :nums [4 3 2], :ops [+ -]}
;; {:result 6, :nums [4 2 3], :ops [- *]}
;; {:result 10, :nums [2 3 4], :ops [* +]}
;; {:result 10, :nums [3 2 4], :ops [* +]}
;; {:result 10, :nums [3 4 2], :ops [* -]}
;; {:result 10, :nums [4 3 2], :ops [* -]}
;; {:result 11, :nums [2 4 3], :ops [* +]}
;; {:result 11, :nums [4 2 3], :ops [* +]}
;; {:result 14, :nums [3 4 2], :ops [* +]}
;; {:result 14, :nums [3 4 2], :ops [+ *]}
;; {:result 14, :nums [4 3 2], :ops [* +]}
;; {:result 14, :nums [4 3 2], :ops [+ *]}
;; {:result 18, :nums [2 4 3], :ops [+ *]}
;; {:result 18, :nums [4 2 3], :ops [+ *]}
;; {:result 20, :nums [2 3 4], :ops [+ *]}
;; {:result 20, :nums [3 2 4], :ops [+ *]})