Skip to content

Instantly share code, notes, and snippets.

Embed
What would you like to do?
sudoku_compact.clj
;; based on core.logic 0.8-alpha2 or core.logic master branch
(ns sudoku
(:refer-clojure :exclude [==])
(:use clojure.core.logic))
(defn get-square [rows x y]
(for [x (range x (+ x 3))
y (range y (+ y 3))]
(get-in rows [x y])))
(defn init [vars hints]
(if (seq vars)
(let [hint (first hints)]
(all
(if-not (zero? hint)
(== (first vars) hint)
succeed)
(init (next vars) (next hints))))
succeed))
(defn sudokufd [hints]
(let [vars (repeatedly 81 lvar)
rows (->> vars (partition 9) (map vec) (into []))
cols (apply map vector rows)
sqs (for [x (range 0 9 3)
y (range 0 9 3)]
(get-square rows x y))]
(run 1 [q]
(== q vars)
(everyg #(infd % (domain 1 2 3 4 5 6 7 8 9)) vars)
(init vars hints)
(everyg distinctfd rows)
(everyg distinctfd cols)
(everyg distinctfd sqs))))
;; ====
(comment
(sudokufd
[0 0 3 0 2 0 6 0 0
9 0 0 3 0 5 0 0 1
0 0 1 8 0 6 4 0 0
0 0 8 1 0 2 9 0 0
7 0 0 0 0 0 0 0 8
0 0 6 7 0 8 2 0 0
0 0 2 6 0 9 5 0 0
8 0 0 2 0 3 0 0 9
0 0 5 0 1 0 3 0 0])
)
@orb
Copy link

orb commented Jun 28, 2013

@postspectacular - it's in clojure.core.logic.fd now. Here's an updated version that I've been using in my core.logic talks:

https://gist.github.com/orb/5884956

@theronic
Copy link

theronic commented May 1, 2017

Dead link: http://dosync.posterous.com/friendlier-shorter. Posterous Spaces are no longer available. Has this been republished elsewhere?

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment