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@gnuvince
Created February 5, 2009 19:08
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(def opening-brackets "({[<")
(def closing-brackets ")}]>")
(def brackets (reduce #(apply assoc %1 %2) {}
(map vector opening-brackets closing-brackets)))
(defn- check-aux [[x & xs] stack]
(if x
(cond (some #{x} opening-brackets) (recur xs (conj stack (brackets x)))
(some #{x} closing-brackets) (if (= x (peek stack))
(recur xs (pop stack))
false)
:else (recur xs stack))
(empty? stack)))
(defn check-brackets [s]
(check-aux s []))
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