Implement current 2019 AoC solutions in Nim

5 files changed, 183 insertions, 0 deletions

diff --git a/2019/eight.nim b/2019/eight.nim
new file mode 100644
index 0000000..ecf291e
--- /dev/null
+++ b/2019/eight.nim
@@ -0,0 +1,30 @@
+# Day Eight: Space Image Format
+import os, strutils, sequtils
+
+let
+  input: string = paramStr(1)
+  digits: string = strip(readFile(input))
+  width: int = 25
+  height: int = 6
+  depth: int = len(digits) div (width * height)
+
+var min, product: int = width * height
+for layer in distribute(@digits, depth):
+  if count(layer, '0') < min:
+    min = count(layer, '0')
+    product = count(layer, '1') * count(layer, '2')
+echo product
+
+for column in 0 ..< height:
+  for row in 0 ..< width:
+    for layer in 0 ..< depth:
+      case digits[(layer * height * width) + (column * width) + row]
+      of '0':
+        write(stdout, ' ')
+        break
+      of '1':
+        write(stdout, 'X')
+        break
+      else:
+        discard
+  write(stdout, '\n')
diff --git a/2019/five.nim b/2019/five.nim
new file mode 100644
index 0000000..87c359e
--- /dev/null
+++ b/2019/five.nim
@@ -0,0 +1,63 @@
+# Day Five: Sunny with a Chance of Asteroids
+import os, strutils, sequtils
+
+let input: string = paramStr(1)
+var program: seq[int] = map(split(strip(readFile(input)), ','), parseInt)
+
+var i: int = 0
+while i < len(program):
+  let opcode: int = program[i] mod 100
+
+  var
+    mode:  int = program[i] div 100
+    one:   int = i+1
+    two:   int = i+2
+    three: int = i+3
+  if len(program)-i > 1 and mode mod 10 == 0:
+    one = program[one]
+  if len(program)-i > 2 and mode div 10 mod 10 == 0:
+    two = program[two]
+  if len(program)-i > 3 and mode div 100 == 0:
+    three = program[three]
+
+  case opcode
+  of 1:   # adds
+    program[three] = program[one] + program[two]
+    i += 4
+  of 2:   # multiplies
+    program[three] = program[one] * program[two]
+    i += 4
+  of 3:   # input
+    write(stdout, "Input: ")
+    program[one] = parseInt(readLine(stdin))
+    i += 2
+  of 4:   # output
+    echo program[one]
+    i += 2
+  of 5:   # jump-if-true
+    if program[one] != 0:
+      i = program[two]
+    else:
+      i += 3
+  of 6:   # jump-if-false
+    if program[one] == 0:
+      i = program[two]
+    else:
+      i += 3
+  of 7:   # less than
+    if program[one] < program[two]:
+      program[three] = 1
+    else:
+      program[three] = 0
+    i += 4
+  of 8:   # equals
+    if program[one] == program[two]:
+      program[three] = 1
+    else:
+      program[three] = 0
+    i += 4
+  of 99:  # terminate
+    break
+  else:
+    echo("Unsupported code ", program[i], " at ", i)
+    quit(QuitFailure)
diff --git a/2019/four.nim b/2019/four.nim
new file mode 100644
index 0000000..eb6d933
--- /dev/null
+++ b/2019/four.nim
@@ -0,0 +1,37 @@
+# Day Four: Secure Container
+import os, strutils, sequtils
+
+let input: string = paramStr(1)
+let bounds: seq[int] = map(split(strip(readFile(input)), '-'), parseInt)
+var valid, details: int = 0
+
+proc criteria(password: int): bool =
+  var password: string = $password
+  for digit in 0 .. 4:
+    if password[digit] > password[digit+1]:
+      return false
+  for digit in 0 .. 4:
+    if password[digit] == password[digit+1]:
+      return true
+  return false
+
+proc extracriteria(password: int): bool =
+  var password: string = $password
+  for digit in 0 .. 4:
+    if password[digit] > password[digit+1]:
+      return false
+  for digit in 0 .. 4:
+    if password[digit] == password[digit+1]:
+      if digit == 0 or password[digit] != password[digit-1]:
+        if digit == 4 or password[digit] != password[digit+2]:
+          return true
+  return false
+
+for password in bounds[0] .. bounds[1]:
+  if criteria(password): inc(valid)
+
+for password in bounds[0] .. bounds[1]:
+  if extracriteria(password): inc(details)
+
+echo valid
+echo details
diff --git a/2019/one.nim b/2019/one.nim
new file mode 100644
index 0000000..63c1219
--- /dev/null
+++ b/2019/one.nim
@@ -0,0 +1,16 @@
+# Day One: The Tyranny of the Rocket Equation
+import os, strutils
+
+let input: string = paramStr(1)
+var sum, fuelsum: int = 0
+
+for mass in lines(input):
+  var fuel = parseInt(mass) div 3 - 2
+  sum += fuel
+  fuelsum += fuel
+  while fuel > 0:
+    fuel = fuel div 3 - 2
+    fuelsum += max(0, fuel)
+
+echo sum
+echo fuelsum
diff --git a/2019/two.nim b/2019/two.nim
new file mode 100644
index 0000000..c0bfb9b
--- /dev/null
+++ b/2019/two.nim
@@ -0,0 +1,37 @@
+# Day Two: 1202 Program Alarm
+import os, strutils, sequtils
+
+let input: string = paramStr(1)
+var program: seq[int] = map(split(strip(readFile(input)), ','), parseInt)
+program[1] = 12
+program[2] = 2
+
+proc execute(program: seq[int]): int =
+  var program: seq[int] = program
+  var i: int = 0
+  while i < len(program):
+    case program[i]
+    of 1:
+      program[program[i+3]] = program[program[i+1]] + program[program[i+2]]
+      i += 4
+    of 2:
+      program[program[i+3]] = program[program[i+1]] * program[program[i+2]]
+      i += 4
+    of 99:
+      break
+    else:
+      echo("Unsupported code ", program[i], " at ", i)
+      quit(QuitFailure)
+  return program[0]
+
+proc grammar(program: seq[int]): int =
+  var program: seq[int] = program
+  for noun in 0 ..< len(program):
+    for verb in 0 ..< len(program):
+      program[1] = noun
+      program[2] = verb
+      if execute(program) == 19690720:
+        return 100 * noun + verb
+
+echo execute(program)
+echo grammar(program)