Day 4 Part 1

diff --git a/src/common.fnl b/src/common.fnl
index c2974c07bbf73a01055f9cf2a20d8909edee03ca..e39868c837e5bdc20a3a10990ac17543427d7309 100644 (file)
--- a/src/common.fnl
+++ b/src/common.fnl
@@ -16,6 +16,8 @@
 
 (defn map [f tbl] (icollect [_ v (ipairs tbl)] (f v)))
 
+(defn filter [f tbl] (icollect [_ v (ipairs tbl)] (if (f v) v nil)))
+
 (defn add [a b] (+ a b))
 
 (defn gt [a b] (> a b))

diff --git a/src/day00.fnl b/src/day00.fnl
new file mode 100644 (file)
index 0000000..79e9c19
--- /dev/null
+++ b/src/day00.fnl
@@ -0,0 +1,15 @@
+(module net.journcy.aoc2022.day00
+  {autoload {c net.journcy.aoc2022.common}})
+
+(comment
+)
+
+(defn part1 [lines]
+  )
+
+(defn part2 [lines]
+  )
+
+(comment
+  (part1 (c.lines "input/day00.txt"))
+  (part2 (c.lines "input/day00.txt")))

diff --git a/src/day04.fnl b/src/day04.fnl
new file mode 100644 (file)
index 0000000..5d42214
--- /dev/null
+++ b/src/day04.fnl
@@ -0,0 +1,42 @@
+(module net.journcy.aoc2022.day04
+  {autoload {c net.journcy.aoc2022.common}})
+
+(defn parse-range [rangestr]
+  (c.map tonumber (c.split rangestr "-")))
+
+(defn parse-pair [pairstr]
+  (c.map parse-range (c.split pairstr ",")))
+
+(defn range-contains [r1 r2]
+  (let [[r1l r1h] r1
+        [r2l r2h] r2]
+    (or (and (>= r2l r1l) (<= r2h r1h))
+        (and (>= r1l r2l) (<= r1h r2h)))))
+
+(comment
+  (parse-range "2-4")
+  (parse-pair "2-4,6-8")
+  (range-contains (unpack (parse-pair "2-8,3-7")))
+  (range-contains (unpack (parse-pair "5-7,7-9")))
+  (range-contains (unpack (parse-pair "6-6,4-6")))
+  (part1 ["2-4,6-8"
+          "2-3,4-5"
+          "5-7,7-9"
+          "2-8,3-7"
+          "6-6,4-6"
+          "2-6,4-8"])
+  )
+
+
+(defn part1 [lines]
+  (->> lines 
+       (c.map parse-pair)
+       (c.filter #(range-contains (unpack $1)))
+       (#)))
+
+(defn part2 [lines]
+  )
+
+(comment
+  (part1 (c.lines "input/day04.txt"))
+  (part2 (c.lines "input/day04.txt")))