Naïve Prime Factorization in Clojure Pt. 2
up vote
0
down vote
favorite
After my last review request, I decided to try and make a "tree" visualization, and thought that I could benefit from making find-prime-factors lazily produce prime factors so the visualization can be updated in real time as factors are found.
This is what I ended up with. I was actually surprised how easy it was to adapt the loop to a recursive lazy-seq solution. The non-return accumulators were added as parameters to a recursive function, and the lazy return list was created via the typical (lazy-seq (cons ... ...)). It actually performs identically to the previous strict version too when evaluation is forced using vec.
If anyone sees anything here that can be commented on, I'd like to know.
(doseq [p (lazily-find-prime-factors 99930610001)]
(println p
(int (/ (System/currentTimeMillis) 1000))))
163 1544998649
191 1544998692
3209797 1544998692
Same as in the last review:
(ns irrelevant.prime-factorization.prime-factorization)
(defn is-factor-of? [n multiple]
(zero? (rem n multiple)))
(defn prime? [n]
(or (= n 2) ; TODO: Eww
(->> (range 2 (inc (Math/sqrt ^double n)))
(some #(is-factor-of? n %))
(not))))
(defn primes
(->> (range)
(drop 2) ; Lower bound of 2 for the range
(filter prime?)))
(defn smallest-factor-of? [n possible-multiples]
(some #(when (is-factor-of? n %) %)
possible-multiples))
Updated:
(defn lazily-find-prime-factors [n]
(letfn [(rec [remaining remaining-primes]
(when-let [small-prime (and (> remaining 1)
(smallest-factor-of? remaining remaining-primes))]
(lazy-seq
(cons small-prime
(rec (long (/ remaining small-prime))
(drop-while #(not= % small-prime) remaining-primes))))))]
(rec n (primes))))
primes clojure
asked 29 mins ago
Carcigenicate
2,70811229
add a comment |
up vote
0
down vote
favorite
After my last review request, I decided to try and make a "tree" visualization, and thought that I could benefit from making find-prime-factors lazily produce prime factors so the visualization can be updated in real time as factors are found.
This is what I ended up with. I was actually surprised how easy it was to adapt the loop to a recursive lazy-seq solution. The non-return accumulators were added as parameters to a recursive function, and the lazy return list was created via the typical (lazy-seq (cons ... ...)). It actually performs identically to the previous strict version too when evaluation is forced using vec.
If anyone sees anything here that can be commented on, I'd like to know.
(doseq [p (lazily-find-prime-factors 99930610001)]
(println p
(int (/ (System/currentTimeMillis) 1000))))
163 1544998649
191 1544998692
3209797 1544998692
Same as in the last review:
(ns irrelevant.prime-factorization.prime-factorization)
(defn is-factor-of? [n multiple]
(zero? (rem n multiple)))
(defn prime? [n]
(or (= n 2) ; TODO: Eww
(->> (range 2 (inc (Math/sqrt ^double n)))
(some #(is-factor-of? n %))
(not))))
(defn primes
(->> (range)
(drop 2) ; Lower bound of 2 for the range
(filter prime?)))
(defn smallest-factor-of? [n possible-multiples]
(some #(when (is-factor-of? n %) %)
possible-multiples))
Updated:
(defn lazily-find-prime-factors [n]
(letfn [(rec [remaining remaining-primes]
(when-let [small-prime (and (> remaining 1)
(smallest-factor-of? remaining remaining-primes))]
(lazy-seq
(cons small-prime
(rec (long (/ remaining small-prime))
(drop-while #(not= % small-prime) remaining-primes))))))]
(rec n (primes))))
primes clojure
asked 29 mins ago
Carcigenicate
2,70811229
add a comment |
up vote
0
down vote
favorite
up vote
0
down vote
favorite
After my last review request, I decided to try and make a "tree" visualization, and thought that I could benefit from making find-prime-factors lazily produce prime factors so the visualization can be updated in real time as factors are found.
This is what I ended up with. I was actually surprised how easy it was to adapt the loop to a recursive lazy-seq solution. The non-return accumulators were added as parameters to a recursive function, and the lazy return list was created via the typical (lazy-seq (cons ... ...)). It actually performs identically to the previous strict version too when evaluation is forced using vec.
If anyone sees anything here that can be commented on, I'd like to know.
(doseq [p (lazily-find-prime-factors 99930610001)]
(println p
(int (/ (System/currentTimeMillis) 1000))))
163 1544998649
191 1544998692
3209797 1544998692
Same as in the last review:
(ns irrelevant.prime-factorization.prime-factorization)
(defn is-factor-of? [n multiple]
(zero? (rem n multiple)))
(defn prime? [n]
(or (= n 2) ; TODO: Eww
(->> (range 2 (inc (Math/sqrt ^double n)))
(some #(is-factor-of? n %))
(not))))
(defn primes
(->> (range)
(drop 2) ; Lower bound of 2 for the range
(filter prime?)))
(defn smallest-factor-of? [n possible-multiples]
(some #(when (is-factor-of? n %) %)
possible-multiples))
Updated:
(defn lazily-find-prime-factors [n]
(letfn [(rec [remaining remaining-primes]
(when-let [small-prime (and (> remaining 1)
(smallest-factor-of? remaining remaining-primes))]
(lazy-seq
(cons small-prime
(rec (long (/ remaining small-prime))
(drop-while #(not= % small-prime) remaining-primes))))))]
(rec n (primes))))
primes clojure
asked 29 mins ago
Carcigenicate
2,70811229
After my last review request, I decided to try and make a "tree" visualization, and thought that I could benefit from making find-prime-factors lazily produce prime factors so the visualization can be updated in real time as factors are found.
This is what I ended up with. I was actually surprised how easy it was to adapt the loop to a recursive lazy-seq solution. The non-return accumulators were added as parameters to a recursive function, and the lazy return list was created via the typical (lazy-seq (cons ... ...)). It actually performs identically to the previous strict version too when evaluation is forced using vec.
If anyone sees anything here that can be commented on, I'd like to know.
(doseq [p (lazily-find-prime-factors 99930610001)]
(println p
(int (/ (System/currentTimeMillis) 1000))))
163 1544998649
191 1544998692
3209797 1544998692
Same as in the last review:
(ns irrelevant.prime-factorization.prime-factorization)
(defn is-factor-of? [n multiple]
(zero? (rem n multiple)))
(defn prime? [n]
(or (= n 2) ; TODO: Eww
(->> (range 2 (inc (Math/sqrt ^double n)))
(some #(is-factor-of? n %))
(not))))
(defn primes
(->> (range)
(drop 2) ; Lower bound of 2 for the range
(filter prime?)))
(defn smallest-factor-of? [n possible-multiples]
(some #(when (is-factor-of? n %) %)
possible-multiples))
Updated:
(defn lazily-find-prime-factors [n]
(letfn [(rec [remaining remaining-primes]
(when-let [small-prime (and (> remaining 1)
(smallest-factor-of? remaining remaining-primes))]
(lazy-seq
(cons small-prime
(rec (long (/ remaining small-prime))
(drop-while #(not= % small-prime) remaining-primes))))))]
(rec n (primes))))
primes clojure
primes clojure
asked 29 mins ago
Carcigenicate
2,70811229
asked 29 mins ago
Carcigenicate
2,70811229
asked 29 mins ago
Carcigenicate
2,70811229
asked 29 mins ago
Carcigenicate
2,70811229
asked 29 mins ago
Carcigenicate
2,70811229
2,70811229
add a comment |
add a comment |
active
oldest
votes
Your Answer
StackExchange.ifUsing("editor", function () {
return StackExchange.using("mathjaxEditing", function () {
StackExchange.MarkdownEditor.creationCallbacks.add(function (editor, postfix) {
StackExchange.mathjaxEditing.prepareWmdForMathJax(editor, postfix, [["\$", "\$"]]);
});
});
}, "mathjax-editing");
StackExchange.ifUsing("editor", function () {
StackExchange.using("externalEditor", function () {
StackExchange.using("snippets", function () {
StackExchange.snippets.init();
});
});
}, "code-snippets");
StackExchange.ready(function() {
var channelOptions = {
tags: "".split(" "),
id: "196"
};
initTagRenderer("".split(" "), "".split(" "), channelOptions);
StackExchange.using("externalEditor", function() {
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled) {
StackExchange.using("snippets", function() {
createEditor();
});
}
else {
createEditor();
}
});
function createEditor() {
StackExchange.prepareEditor({
heartbeatType: 'answer',
convertImagesToLinks: false,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: null,
bindNavPrevention: true,
postfix: "",
imageUploader: {
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
},
onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
});
}
});
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fcodereview.stackexchange.com%2fquestions%2f209786%2fna%25c3%25afve-prime-factorization-in-clojure-pt-2%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
active
oldest
votes
active
oldest
votes
active
oldest
votes
active
oldest
votes
Thanks for contributing an answer to Code Review Stack Exchange!
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
Use MathJax to format equations. MathJax reference.
To learn more, see our tips on writing great answers.
Some of your past answers have not been well-received, and you're in danger of being blocked from answering.
Please pay close attention to the following guidance:
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
To learn more, see our tips on writing great answers.
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fcodereview.stackexchange.com%2fquestions%2f209786%2fna%25c3%25afve-prime-factorization-in-clojure-pt-2%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
