aoc

commit 020de432cbba41142302e5e654f8251aa37aff60 (patch)
parent 6a646f375e801d789c4c402aa128194012785f0b
Author: Alex Karle <alex@alexkarle.com>
Date:   Wed, 23 Nov 2022 09:39:24 -0500

day1/2: Add some scheme solutions

All in the name of learning some CHICKEN :)

Diffstat:
A
01/sol.scm
 | 
35
+++++++++++++++++++++++++++++++++++
A
02/sol.scm
 | 
41
+++++++++++++++++++++++++++++++++++++++++

2 files changed, 76 insertions(+), 0 deletions(-)
diff --git a/01/sol.scm b/01/sol.scm
@@ -0,0 +1,35 @@
+(import (chicken io))
+
+(define (read-num port)
+  (let ((line (read-line port)))
+    (if (eof-object? line)
+	#f
+	(string->number line))))
+
+(define (part-1 port)
+  (let loop ((total 0) (prev #f) (num (read-num port)))
+    (define (next)
+      (loop total num (read-num port)))
+    (cond ((not num) total)
+	  ((not prev) (next))
+	  ((< prev num) (loop (add1 total) num (read-num port)))
+	  (else (next)))))
+
+(define (winsum vect)
+  (apply + (vector->list vect)))
+
+(define (part-2 port)
+  (let loop ((i 0) (total 0) (window #(0 0 0)) (num (read-num port)))
+    (if (not num)
+	total
+	(let ((old-val (winsum window)))
+	  (vector-set! window (modulo i 3) num)
+	  (if (and (> i 2) (< old-val (winsum window)))
+	      (loop (add1 i) (add1 total) window (read-num port))
+	      (loop (add1 i) total window (read-num port)))))))
+
+(call-with-input-file "input"
+  (lambda (p) (print (part-1 p))))
+
+(call-with-input-file "input"
+  (lambda (p) (print (part-2 p))))
diff --git a/02/sol.scm b/02/sol.scm
@@ -0,0 +1,41 @@
+(import (chicken io)
+        (chicken string))
+
+(define (part-1 port)
+  (let loop ((h 0) (d 0))
+    (let ((l (read-line port)))
+      (if (eof-object? l)
+        (* h d)
+        (let* ((parts (string-split l))
+               (act (car parts))
+               (mag (string->number (cadr parts))))
+          (cond ((equal? act "down")
+                 (loop h (+ d mag)))
+                ((equal? act "up")
+                 (loop h (- d mag)))
+                ((equal? act "forward")
+                 (loop (+ h mag) d))
+                (else (error "Bad action " act))))))))
+
+(define (part-2 port)
+  (let loop ((h 0) (d 0) (a 0))
+    (let ((l (read-line port)))
+      (if (eof-object? l)
+        (* h d)
+        (let* ((parts (string-split l))
+               (act (car parts))
+               (mag (string->number (cadr parts))))
+          (cond ((equal? act "down")
+                 (loop h d (+ a mag)))
+                ((equal? act "up")
+                 (loop h d (- a mag)))
+                ((equal? act "forward")
+                 (loop (+ h mag) (+ d (* a mag)) a))
+                (else (error "Bad action " act))))))))
+
+
+(call-with-input-file "input"
+                      (lambda (p) (print (part-1 p))))
+
+(call-with-input-file "input"
+                      (lambda (p) (print (part-2 p))))