day 2 racket

rkt/02.1.rkt

@@ -0,0 +1,17 @@
+#lang racket
+
+(let-values ([(x y)
+  (with-input-from-file "../input/02"
+    (lambda ()
+      (for/fold ([x 0]
+                 [y 0])
+                ([line (in-lines)])
+        (let ([s (string-split line)])
+        (let ([op (car s)]
+              [num (string->number (car (cdr s)))])
+          (match op
+            ["up" (values x (- y num))]
+            ["down" (values x (+ y num))]
+            ["forward" (values (+ x num) y)]))))))
+]) (values (cons x y) (* x y)))
+

rkt/02.2.rkt

@@ -0,0 +1,18 @@
+#lang racket
+
+(let-values ([(_ x y)
+  (with-input-from-file "../input/02"
+    (lambda ()
+      (for/fold ([aim 0]
+                 [x 0]
+                 [y 0])
+                ([line (in-lines)])
+        (let ([s (string-split line)])
+        (let ([op (car s)]
+              [num (string->number (car (cdr s)))])
+          (match op
+            ["up" (values (- aim num) x y)]
+            ["down" (values (+ aim num) x y)]
+            ["forward" (values aim (+ x num) (+ y (* aim num)))]))))))
+]) (values (cons x y) (* x y)))
+