(ns examples.codebreaker

(:use clojure.contrib.seq-utils

clojure.contrib.test-is

clojure.set))

(defn count-if [f coll]

(count (filter f coll)))

(defn count-exact-match

"Number of exact matches (same color, same position)."

[secret guess]

(count-if true? (map = secret guess)))

(defn shared-frequencies

"Returns a map with

[secret guess]

(let [secret-dist (frequencies secret)

guess-dist (frequencies guess)

shared-colors (intersection (set (keys secret-dist))

(set (keys guess-dist)))]

(zipmap shared-colors

(map #(min (secret-dist %) (guess-dist %))

shared-colors))))

(defn count-color-match

"Number of color matches (same color, maybe different position)."

[secret guess]

(apply + (vals (shared-frequencies secret guess))))

(defn codebreaker-score

"Returns a string of the form b*w*, with a number of bs equal

[secret guess]

(let [black-count (count-exact-match secret guess)

white-count (- (count-color-match secret guess) black-count)]

(apply str

(concat (repeat black-count "b")

(repeat white-count "w")))))