Day 14 progress

2020/src/aoc2020.nim

@@ -9,4 +9,4 @@ proc solve_for_day(n: int) {.used.} =
 
 when isMainModule:
   # solve_all()
-  solve_for_day(13)
+  solve_for_day(14)

2020/src/day14.nim

@@ -0,0 +1,46 @@
+import streams, strutils, bitops, tables
+
+proc asMasks(s: string): (uint64, uint64) =
+  var ones, zeroes = 0'u64
+  for c in s:
+    ones = rotateLeftBits(ones, 1'u8)
+    zeroes = rotateLeftBits(zeroes, 1'u8)
+    case c:
+      of '1': ones.setBit(0'u8)
+      of '0': zeroes.setBit(0'u8)
+      else: discard
+  echo ("Masks:", ones, zeroes)
+  return (ones, zeroes)
+
+doAssert "01X".asMasks() == (2'u64, 4'u64)
+
+proc withMasks(n: uint64, mask: (uint64, uint64)): uint64 =
+  echo n.toBin
+  n.bitand(mask[1]).bitnot.bitand(mask[0].bitnot).bitnot
+
+proc part1*(s: Stream): int =
+  var masks: (uint64, uint64)
+  var memory = newTable[uint64, uint64]()
+  var i = 0
+  for l in s.lines:
+    if l.startsWith("mask = "):
+      masks = l.split(" = ")[1].asMasks
+    elif l.startsWith("mem["):
+      let ll = l.split("[")[1].split("] = ")
+      memory[ll[0].parseUInt] = ll[1].parseUInt.withMasks(masks)
+    inc i
+  echo memory
+  for v in memory.values: result += int v
+
+  # 9,639,694,085,526 is too high
+
+let n = """
+mask = XXXXXXXXXXXXXXXXXXXXXXXXXXXXX1XXXX0X
+mem[8] = 11
+mem[7] = 101
+mem[8] = 0
+""".newStringStream.part1()
+echo n
+doAssert n == 165
+
+proc part2*(s: Stream): int =9