From 0e5d9eca75997bc32d4edcdd2e9693ed31d1416f Mon Sep 17 00:00:00 2001
From: Matthew Butterick <mb@mbtype.com>
Date: Mon, 2 Dec 2019 06:03:52 -0800
Subject: [PATCH] 2019 d01 & d02

---
 2019/01.rkt  |  20 +++++++++++
 2019/01.rktd | 100 +++++++++++++++++++++++++++++++++++++++++++++++++++
 2019/02.rkt  |  36 +++++++++++++++++++
 2019/02.rktd |   1 +
 4 files changed, 157 insertions(+)
 create mode 100644 2019/01.rkt
 create mode 100644 2019/01.rktd
 create mode 100644 2019/02.rkt
 create mode 100644 2019/02.rktd

diff --git a/2019/01.rkt b/2019/01.rkt
new file mode 100644
index 0000000..b776246
--- /dev/null
+++ b/2019/01.rkt
@@ -0,0 +1,20 @@
+#lang br
+(require racket/file rackunit)
+
+(define (fuel-required mass) (- (floor (/ mass 3)) 2))
+
+(define masses
+  (for/list ([ln (in-port read (open-input-file "01.rktd"))])
+            ln))
+
+;; 1
+(check-eq? (apply + (map fuel-required masses)) 3167282)
+
+(define (recursive-fuel mass [acc 0])
+  (match (fuel-required mass)
+    [(? positive? fuel)
+     (recursive-fuel fuel (+ acc fuel))]
+    [else acc]))
+
+;; 2
+(check-eq? (apply + (map recursive-fuel masses)) 4748063)
\ No newline at end of file
diff --git a/2019/01.rktd b/2019/01.rktd
new file mode 100644
index 0000000..6e9d1fc
--- /dev/null
+++ b/2019/01.rktd
@@ -0,0 +1,100 @@
+143754
+83242
+124730
+62796
+128187
+68925
+60687
+68800
+112450
+70696
+94653
+62124
+82251
+91514
+79895
+82973
+71678
+141671
+88243
+109553
+135097
+78026
+100048
+52113
+109934
+92274
+62821
+138384
+90112
+114684
+137383
+71727
+143236
+79842
+101187
+71202
+131156
+128805
+105102
+71319
+88615
+62024
+126027
+55321
+91226
+75020
+136689
+70265
+97850
+96536
+135311
+64962
+87137
+50402
+70604
+56879
+60016
+98231
+136635
+64590
+143522
+112152
+142511
+95350
+83483
+123681
+123792
+99044
+139282
+96610
+116844
+50416
+110682
+55137
+69795
+100411
+110119
+141558
+90780
+108063
+102247
+85487
+107174
+79009
+131908
+95164
+120588
+62031
+51070
+63773
+128565
+96458
+91388
+54345
+52840
+130519
+51357
+146851
+68455
+102463
\ No newline at end of file
diff --git a/2019/02.rkt b/2019/02.rkt
new file mode 100644
index 0000000..a0a0dc6
--- /dev/null
+++ b/2019/02.rkt
@@ -0,0 +1,36 @@
+#lang br
+(require racket/file rackunit)
+
+(define (string->regs str)
+  (list->vector (map string->number (string-split str ","))))
+
+(define (solve regs)
+  (define (deref ptr) (vector-ref regs ptr))
+  (let loop ([ptr 0])
+    (match (vector-ref regs ptr)
+      [(and (or 1 2) opcode)
+       (vector-set! regs (deref (+ ptr 3))
+                    ((match opcode [1 +][_ *])
+                     (deref (deref (+ ptr 1)))
+                     (deref (deref (+ ptr 2)))))
+       (loop (+ ptr 4))]
+      [99 regs])))
+
+(define test "1,1,1,4,99,5,6,0,99")
+(check-equal? (solve (string->regs test)) '#(30 1 1 4 2 5 6 0 99))
+
+(define (nv-result noun verb)
+  (define regs (string->regs (file->string "02.rktd")))
+  (vector-set*! regs 1 noun 2 verb)
+  (vector-ref (solve regs) 0))
+
+;; 1
+(check-eq? (nv-result 12 2) 6730673)
+
+;; 2
+(check-eq?
+ (for*/first ([noun (in-range 91)]
+              [verb (in-range 91)]
+              #:when (eq? (nv-result noun verb) 19690720))
+             (+ (* 100 noun) verb))
+ 3749)
\ No newline at end of file
diff --git a/2019/02.rktd b/2019/02.rktd
new file mode 100644
index 0000000..af1c639
--- /dev/null
+++ b/2019/02.rktd
@@ -0,0 +1 @@
+1,0,0,3,1,1,2,3,1,3,4,3,1,5,0,3,2,9,1,19,1,19,6,23,2,6,23,27,2,27,9,31,1,5,31,35,1,35,10,39,2,39,9,43,1,5,43,47,2,47,10,51,1,51,6,55,1,5,55,59,2,6,59,63,2,63,6,67,1,5,67,71,1,71,9,75,2,75,10,79,1,79,5,83,1,10,83,87,1,5,87,91,2,13,91,95,1,95,10,99,2,99,13,103,1,103,5,107,1,107,13,111,2,111,9,115,1,6,115,119,2,119,6,123,1,123,6,127,1,127,9,131,1,6,131,135,1,135,2,139,1,139,10,0,99,2,0,14,0
\ No newline at end of file