1 files changed, 41 insertions, 0 deletions
diff --git a/2015/day-05/day-05.rkt b/2015/day-05/day-05.rkt
new file mode 100644
index 0000000..9714a0f
--- /dev/null
+++ b/2015/day-05/day-05.rkt
@@ -0,0 +1,41 @@
+#lang racket
+(require "../../jj-aoc.rkt"
+         threading)
+
+(define strs (port->lines (open-day 5 2015)))
+
+;; part 1
+(define (at-least-three-vowels? str)
+  (~>> str
+       (regexp-replace* #px"[^aeiou]" _ "")
+       string-length
+       (<= 3)))
+
+(define (at-least-one-pair? str)
+  (regexp-match? #px"(.)\\1{1,}" str))
+
+(define (no-forbidden-pairs? str)
+  (~>> (list "ab" "cd" "pq" "xy")
+       (ormap (λ~>> (string-contains? str)))
+       not))
+
+(define (nice? str)
+  (~>> (list at-least-three-vowels?
+             at-least-one-pair?
+             no-forbidden-pairs?)
+       (andmap (λ (f) (f str)))))
+
+(count nice? strs)
+
+;; part 2
+(define (repeating-pair? str)
+  (regexp-match? #px"(..).*\\1" str))
+
+(define (symmetry? str)
+  (regexp-match? #px"(.).\\1" str))
+
+(define (new-nice? str)
+  (~>> (list repeating-pair? symmetry?)
+       (andmap (λ (f) (f str)))))
+
+(count new-nice? strs)
+\ No newline at end of file