day5: part2 lisp

2015/days/05/nice2.lisp

@@ -0,0 +1,46 @@
+(defun twice? (string pattern)
+  (numberp (search pattern string
+                   :start2 (+
+                            (search pattern string)
+                            (length pattern)))))
+
+
+(defvar pattern)
+
+(defun overtwice? (string)
+  (loop for i from 0 to (- (length string) 2)
+        do
+           (setq pattern (subseq string i (+ i 2)))
+           (if (twice? string pattern)
+               (return-from overtwice? t))
+  )
+  nil)
+
+(defvar c1)
+(defvar c2)
+(defvar c3)
+(defun tandem? (string)
+  (loop for i from 0 to (- (length string) 3)
+        do
+        (setq c1 (char string i))
+        (setq c2 (char string (+ i 1)))
+        (setq c3 (char string (+ i 2)))
+        (if (and (equal c1 c3) (not (equal c1 c2)))
+            (return-from tandem? t)))
+  nil)
+
+(defun nice? (string)
+  (and (overtwice? string)
+       (tandem? string)))
+
+(defvar my-count 0)
+
+(with-open-file (in "./data/input")
+  (do ((line (read-line in nil)
+             (read-line in nil)))
+      ((null line))
+    (if (nice? line)
+        (setq my-count (+ my-count 1)))
+    ))
+
+(print my-count)