From 76030247711a51f1a0d6545d47db0a7b63622a6d Mon Sep 17 00:00:00 2001
From: James Raikes <jzraikes@gmail.com>
Date: Sun, 1 Oct 2017 19:49:55 +0100
Subject: [PATCH] Completed all

---
 .travis.yml    |  4 +-
 src/sudoku.clj | 99 +++++++++++++++++++++++++++++++++++++++++---------
 2 files changed, 83 insertions(+), 20 deletions(-)

diff --git a/.travis.yml b/.travis.yml
index 455f3c0..45c29f6 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,6 +1,6 @@
 language: clojure
-lein: lein2
-script: lein2 midje :config .midje-grading-config.clj
+lein: lein
+script: lein midje :config .midje-grading-config.clj
 jdk:
   - openjdk7
 notifications:
diff --git a/src/sudoku.clj b/src/sudoku.clj
index 5254c46..1c2f381 100644
--- a/src/sudoku.clj
+++ b/src/sudoku.clj
@@ -3,56 +3,119 @@
 
 (def board identity)
 
+(def all-values #{1 2 3 4 5 6 7 8 9})
+
+;(def sudoku-board
+;  (board [[5 3 0 0 7 0 0 0 0]
+;          [6 0 0 1 9 5 0 0 0]
+;          [0 9 8 0 0 0 0 6 0]
+;          [8 0 0 0 6 0 0 0 3]
+;          [4 0 0 8 0 3 0 0 1]
+;          [7 0 0 0 2 0 0 0 6]
+;          [0 6 0 0 0 0 2 8 0]
+;          [0 0 0 4 1 9 0 0 5]
+;          [0 0 0 0 8 0 0 7 9]]))
+;
+;(def solved-board
+;  (board [[5 3 4 6 7 8 9 1 2]
+;          [6 7 2 1 9 5 3 4 8]
+;          [1 9 8 3 4 2 5 6 7]
+;          [8 5 9 7 6 1 4 2 3]
+;          [4 2 6 8 5 3 7 9 1]
+;          [7 1 3 9 2 4 8 5 6]
+;          [9 6 1 5 3 7 2 8 4]
+;          [2 8 7 4 1 9 6 3 5]
+;          [3 4 5 2 8 6 1 7 9]]))
+;
+;(def invalid-board
+;  (board [[5 3 4 6 7 8 9 1 1]
+;          [6 7 2 1 9 5 3 4 8]
+;          [1 9 8 3 4 2 5 6 7]
+;          [8 5 9 7 6 1 4 2 3]
+;          [4 2 6 8 5 3 7 9 1]
+;          [7 1 3 9 2 4 8 5 6]
+;          [9 6 1 5 3 7 2 8 4]
+;          [2 8 7 4 1 9 6 3 5]
+;          [3 4 5 2 8 6 1 7 9]]))
+
 (defn value-at [board coord]
-  nil)
+  (get-in board coord))
 
 (defn has-value? [board coord]
-  nil)
+  (not= 0 (value-at board coord)))
 
 (defn row-values [board coord]
-  nil)
+  (let [[row _] coord]
+     (set (get board row))))
 
 (defn col-values [board coord]
-  nil)
+  (let [[_ col] coord]
+    (set (for [row board]
+           (get row col)))))
 
 (defn coord-pairs [coords]
-  nil)
+  (vec (for [row coords
+             col coords]
+         [row col])))
 
 (defn block-values [board coord]
-  nil)
+  (let [square-coords (coord-pairs [0 1 2])
+        block-corner (mapv #(- % (mod % 3)) coord)]
+    (set (map #(value-at board (map + block-corner %)) square-coords))))
 
 (defn valid-values-for [board coord]
-  nil)
+  (if (has-value? board coord)
+    #{}
+    (set/difference all-values (set/union (row-values board coord)
+                                          (col-values board coord)
+                                          (block-values board coord)))))
 
 (defn filled? [board]
-  nil)
+  (every? #(every? pos? %) board))
+
+(defn valid-set? [a-set]
+  (= all-values a-set))
 
 (defn rows [board]
-  nil)
+  (mapv #(row-values board [% 0]) (range 9)))
 
 (defn valid-rows? [board]
-  nil)
+  (every? valid-set? (rows board)))
 
 (defn cols [board]
-  nil)
+  (mapv #(col-values board [0 %]) (range 9)))
 
 (defn valid-cols? [board]
-  nil)
+  (every? valid-set? (cols board)))
 
 (defn blocks [board]
-  nil)
+  (map #(block-values board %) (coord-pairs [0 3 6])))
 
 (defn valid-blocks? [board]
-  nil)
+  (every? valid-set? (blocks board)))
 
 (defn valid-solution? [board]
-  nil)
+  (every? identity ((juxt valid-cols? valid-rows? valid-blocks?) board)))
 
 (defn set-value-at [board coord new-value]
-  nil)
+  (assoc-in board coord new-value))
 
 (defn find-empty-point [board]
-  nil)
+  (let [row (first (keep-indexed #(when (some zero? %2) %1) board))
+        col (first (keep-indexed #(when (zero? %2) %1) (get board row)))]
+    [row col]))
+
+;(defn solver-helper)
 
 (defn solve [board]
-  nil)
+  (if (filled? board)
+    (if (valid-solution? board)
+      board
+      '())
+    (let [gap (find-empty-point board)]
+      (for [guess (valid-values-for board gap)
+            solution (solve (set-value-at board gap guess))]
+        solution))))
+
+
+