Initial commit

2021/day02/day02.awk

@@ -0,0 +1,6 @@
+/down/ {aim += $2}
+/up/ {aim -= $2}
+/forward/ {pos += $2; depth += aim * $2}
+END {print pos * aim, pos * depth}
+# one-liner
+# /^d/{a+=$2}/u/{a-=$2}/f/{p+=$2;d+=a*$2}END{print p*a,p*d}

2021/day02/day02.c

@@ -0,0 +1,32 @@
+#include <stdio.h>
+
+int main() {
+  char instr[9] = {0};
+  int n = 0;
+
+  int pos = 0;
+  int depth = 0;
+  int aim = 0;
+
+  while (scanf("%s %d\n", instr, &n) == 2) {
+    switch (instr[0]) {
+    case 'd':
+      aim += n;
+      break;
+    case 'u':
+      aim -= n;
+      break;
+    case 'f':
+      pos += n;
+      depth += aim * n;
+      break;
+    default:
+      fprintf(stderr, "unknown instruction: %s", instr);
+      break;
+    }
+  }
+  printf("%d\n", pos * aim);
+  printf("%d\n", pos * depth);
+
+  return 0;
+}

2021/day02/day02.scm

@@ -0,0 +1,30 @@
+(import (chicken io)
+	srfi-1
+	srfi-152
+	matchable)
+
+(define (read-input #!optional (port (current-input-port)))
+  (map (lambda (s) (let ((l (string-split s " ")))
+		     (list (string->symbol (car l))
+			   (string->number (cadr l)))))
+       (read-lines port)))
+
+(define (move steps pos depth aim)
+  (match steps
+    (() (values pos depth aim))
+    ((('down n) . rest) (move rest pos depth (+ aim n)))
+    ((('up n) . rest) (move rest pos depth (- aim n)))
+    ((('forward n) . rest) (move rest (+ pos n) (+ depth (* aim n)) aim))
+    (_ (error "unknown instruction" (car steps)))))
+
+(define (part1 l)
+  (let-values (((pos depth aim) (move l 0 0 0)))
+    (* pos aim)))
+
+(define (part2 l)
+  (let-values (((pos depth aim) (move l 0 0 0)))
+    (* pos depth)))
+
+(let ((in (read-input)))
+  (print (part1 in))
+  (print (part2 in)))

2021/day02/day02_golf.c

@@ -0,0 +1 @@
+c,n,p,d,a;main(){while(scanf("%c%*s%d\n",&c,&n)>1)c^'d'?a+=n:c^'f'?p+=n,d+=a*n:a-=n;printf("%d %d",p*a,p*d);}