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words with duplicate letters

Some words have duplicate letters ("book"—two o's—or "that"—two t's). Many don't.

Your task is to write a predicate that returns true if the string contains any words with duplicate letters.


(duplicate-letter? "Hello, my friend!") => true (because "hello" has two l's)

(duplicate-letter? "Hey friend!") => false (because no words have duplicates)

Have fun with this one! Try out different ways to implement it.

Thanks to to this site for the challenge idea!

(defn duplicate-letter? [s]
(some (comp (partial < 1)
(str/split s #" "))))
(defn duplicate-letter? [s]
(let [words (clojure.string/split s #" ")
letter-freq (map #(vals (frequencies %)) words)
duplicates? (map (fn [xs]
(some #(> % 1) xs))
(some true? duplicates?)))
(defn duplicate-letter? [s]
(if (re-find #"\W" s)
(boolean (some duplicate-letter? (clojure.string/split s #"\W+")))
(not= (count s) (count (set (clojure.string/lower-case s))))))
(defn duplicate-letter? [s]
(not-every? #(= (count (set %)) (count %)) (clojure.string/split s #" ")))
;; case insensitive. treats all characters as 'letters'
(defn wordhasdup [s]
(->> s
(apply max)
(< 1)))
(defn duplicate-letter? [s]
(->> (clojure.string/split s #" ")
(map wordhasdup)
(some true?)
(duplicate-letter? "Fortune favours the bold.") ;; false
(duplicate-letter? "You can lead a horse to water, but you can't make him drink.") ;; false
(duplicate-letter? "Look before you leap.") ;; true
(duplicate-letter? "An apple a day keeps the doctor away.") ;; true
;; clojure.string required as :str
(defn duplicate-letter?-1 [s]
(->> (str/split s #" ")
(map #(not (apply distinct? %))) ;=> true for all words with duplicates
(some true?)))
(defn duplicate-letter?-2 [s]
(->> (str/split s #" ")
(map #(not= (count %) (count (set %))))
(some true?)))
(defn duplicate-letter?-3 [s]
(->> (clojure.string/split s #" ")
(mapcat (comp vals frequencies))
(some #(< 1 %))))
(defn duplicate-letter?
(->> (re-seq #"\w+" s)
(map frequencies)
(map vals)
(apply concat)
(some (partial not= 1))
;;; Some words have duplicate letters ("book"—two o's—or "that"—two t's)
;;; Write a predicate that returns true if the string contains any words
;;; with duplicate letters.
;;; ??? Should upper and lower case of same letter count? (I'll say yes)
;;; ??? Should repeated-digits like "abc111" count? (I'll say no)
;;; ??? Should repeated-punctuation, etc. count? (I'll say no)
(defn reused-letter? [wd]
(let [letters-in-wd (re-seq #"[a-z]" (clojure.string/lower-case wd))]
(not= (count letters-in-wd)
(count (set letters-in-wd)))))
(defn duplicate-letter? [s]
(let [words #(str/split % #"\s+")]
(some reused-letter? (words s))))
(duplicate-letter? "Hello, my friend!") => true
(duplicate-letter? "Hey friend!") => nil
(duplicate-letter? "Huh?") => true
(duplicate-letter? "yow bar baz abc111") => nil
(duplicate-letter? "bar ba%%z") => nil
(defn duplicate-letter?
(some->> (partition 2 1 s)
(filter (partial apply =))
(defn duplicate-letter?
(->> (map = s (rest s))
(drop-while false?)
(defn duplicate-letter? [s]
(let [alph? #(or (and (> % 64) (< % 95)) (and (> % 96) (< % 123)))]
(first (sort > (vals (filter #(alph? (-> % key int)) (frequencies s)))))
(ns duplicate-letters-challenge)
(defn- has-duplicate-letter? [word]
(< (count (distinct word)) (count word)))
(defn duplicate-letter? [s]
(let [words (clojure.string/split s #"\W")]
(boolean (some has-duplicate-letter? words))))
(defn duplicate-letter? [s]
(not (reduce
(fn [acc c] (if (acc c)
(reduced false)
(conj acc c)))
(ns eu.teod.scratch2.newsletter.pftv-359
(:require [clojure.string :as string]))
(let [a (int \a)
z (int \z)
A (int \A)
Z (int \Z)]
(defn ascii-lowercase? [ch]
(let [c (int ch)]
(or (<= A c Z)
(<= a c z)))))
(defn words [sentence]
(for [word-with-punctuation (string/split sentence #"\s")]
(apply str (filter ascii-lowercase? word-with-punctuation))))
(defn word-duplicate-letter? [word]
(not= (count word)
(count (set word))))
(defn duplicate-letter? [sentence]
(reduce #(or %1 %2)
(map word-duplicate-letter? (words sentence))))
(for [case ["Hello, my friend!" "Hey, friend!"]]
[case (duplicate-letter? case)])
;; => (["Hello, my friend!" true] ["Hey, friend!" false])
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