day04

2022/day04/day04.nim

@@ -0,0 +1,32 @@
+import std/[os, setutils, strutils]
+
+proc boundToSet(bound: string): set[uint8] =
+  let lowHigh = bound.split('-')
+  let low = parseInt(lowHigh[0]).uint8
+  let high = parseInt(lowHigh[1]).uint8
+  toSet(low..high)
+
+proc eitherContains(a, b: set[uint8]): bool =
+  a <= b or b < a
+
+proc intersects(a, b: set[uint8]): bool =
+  a * b != {}
+
+let compare =
+  case paramStr(1):
+  of "1":
+    eitherContains
+  of "2":
+    intersects
+  else:
+    eitherContains
+
+var number = 0
+for pair in lines(stdin):
+  let elves = pair.split(',')
+  let s1 = boundToSet(elves[0])
+  let s2 = boundToSet(elves[1])
+  if compare(s1, s2):
+    number.inc
+
+echo number