advent-of-code

commit c420ace3d85d29e8beebe6b58cd84b8f68757810
parent 7c2caea1b2df31b38e53c41606c550fffdc62774
Author: aabacchus <bvnfuller@gmail.com>
Date:   Fri,  3 Dec 2021 00:51:07 +0000

21.2.2

Diffstat:
M
2021/02/2.c
 | 
6
++++--
M
2021/02/2.scm
 | 
8
+++++---

2 files changed, 9 insertions(+), 5 deletions(-)
diff --git a/2021/02/2.c b/2021/02/2.c
@@ -16,6 +16,7 @@ main(int argc, char **argv) {
 	}
 
 	int coords[2] = {0, 0};
+	int aim = 0;
 
 	char *buf = NULL;
 	size_t buflen = 0;
@@ -24,12 +25,13 @@ main(int argc, char **argv) {
 		switch (buf[0]) {
 			case 'f': /* forward */
 				coords[0] += param;
+				coords[1] += param * aim;
 				break;
 			case 'u': /* up */
-				coords[1] -= param;
+				aim -= param;
 				break;
 			case 'd': /* down */
-				coords[1] += param;
+				aim += param;
 				break;
 		}
 	}
diff --git a/2021/02/2.scm b/2021/02/2.scm
@@ -4,11 +4,13 @@
 (define txtlines (call-with-input-file "input" read-lines))
 (define splitlines (map (lambda (s) (string-split s " ")) txtlines))
 
+(define aim 0)
 (define (getvec-line splitline)
   (cond
-    ((string=? (car splitline) "forward") (list (string->number (cadr splitline)) 0))
-    ((string=? (car splitline) "down") (list 0 (string->number (cadr splitline))))
-    ((string=? (car splitline) "up") (list 0 (* -1 (string->number (cadr splitline)))))
+    ((string=? (car splitline) "forward")
+     (let ((p (string->number (cadr splitline)))) (list p (* p aim))))
+    ((string=? (car splitline) "down") (set! aim (+ aim (string->number (cadr splitline)))) (list 0 0))
+    ((string=? (car splitline) "up") (set! aim (+ aim (* -1 (string->number (cadr splitline))))) (list 0 0))
     (else (list 0 0))))
 
 (define (move lines)