aoc

commit b49452ae077000338b765cd24110438b4a0d0099 (patch)
parent 5cd89601cf558e5d22de7c13b5acff4d1a888427
Author: Alex Karle <alex@alexkarle.com>
Date:   Tue,  6 Dec 2022 23:33:27 -0500

day6: Generalize scheme solution, add python sol

Mostly just curious how the python speed stacks up! (hint: its just as
fast).

Diffstat:
A
2022/06/sol.py
 | 
16
++++++++++++++++
M
2022/06/sol.scm
 | 
41
+++++++++++++++--------------------------

2 files changed, 31 insertions(+), 26 deletions(-)
diff --git a/2022/06/sol.py b/2022/06/sol.py
@@ -0,0 +1,16 @@
+import sys
+
+def last_len_uniq(s, i, n):
+    return len({c for c in s[i-n:i]}) == n
+
+s = input()
+
+for i in range(4, len(s) + 1):
+    if last_len_uniq(s, i, 4):
+        print(i)
+        break
+
+for i in range(14, len(s) + 1):
+    if last_len_uniq(s, i, 14):
+        print(i)
+        break
diff --git a/2022/06/sol.scm b/2022/06/sol.scm
@@ -1,33 +1,22 @@
 #!/usr/local/bin/chicken-csi -ss
-(import (chicken io))
-
-(define (uniq lst)
-  (if (null? lst)
-      '()
-      (if (member (car lst) (cdr lst))
-          (uniq (cdr lst))
-          (cons (car lst) (uniq (cdr lst))))))
-
-(define (distinct? lst)
-  (equal? (length lst) (length (uniq lst))))
+(import (chicken io)
+        srfi-1)      ; delete-duplicates
 
 (define (last-len-uniq? s i len)
-  (cond ((< i len) #f)
-        (else (distinct? (string->list (substring s (- i len) i))))))
-
-(define (find-sop s)
-  (let loop ((i 4))
-    (if (last-len-uniq? s i 4)
-        i
-        (loop (add1 i)))))
+  (and (>= i len)
+       (equal? len
+               (length (delete-duplicates (string->list (substring s (- i len) i)))))))
 
-(define (find-som s)
-  (let loop ((i 4))
-    (if (last-len-uniq? s i 14)
-        i
-        (loop (add1 i)))))
+(define (str-find-idx s len-uniq)
+  (let ((n (string-length s)))
+    (let loop ((i 0))
+      (if (>= i n)
+          #f
+          (if (last-len-uniq? s i len-uniq)
+              i
+              (loop (add1 i)))))))
 
 (define (main args)
   (let ((input (read-line)))
-    (print (find-sop input))
-    (print (find-som input))))
+    (print (str-find-idx input 4))
+    (print (str-find-idx input 14))))