From 3aa60c0700bae5a3eeab4720cd3671306ed714df Mon Sep 17 00:00:00 2001
From: Marcel Fries <m.fries@eas-solutions.de>
Date: Mon, 2 Dec 2019 13:52:49 +0100
Subject: [PATCH] Day 1 + 2

---
 .gitignore         |   1 +
 day01/input.txt    | 100 +++++++++++++++++++++++++++++++++++++++++++++
 day01/main.nim     |  24 +++++++++++
 day02/computer.nim |  69 +++++++++++++++++++++++++++++++
 day02/input.txt    |   1 +
 day02/main.nim     |  19 +++++++++
 6 files changed, 214 insertions(+)
 create mode 100644 .gitignore
 create mode 100644 day01/input.txt
 create mode 100644 day01/main.nim
 create mode 100644 day02/computer.nim
 create mode 100644 day02/input.txt
 create mode 100644 day02/main.nim

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..adb36c8
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+*.exe
\ No newline at end of file
diff --git a/day01/input.txt b/day01/input.txt
new file mode 100644
index 0000000..72c227f
--- /dev/null
+++ b/day01/input.txt
@@ -0,0 +1,100 @@
+51360
+95527
+72603
+128601
+68444
+138867
+67294
+134343
+62785
+53088
+134635
+137884
+97654
+103704
+138879
+87561
+83922
+68414
+84876
+105143
+76599
+98924
+57080
+63590
+50126
+111872
+55754
+64410
+78488
+56557
+105446
+127182
+59451
+87249
+61652
+131698
+148820
+95742
+68223
+121744
+65678
+99745
+64089
+75610
+106085
+100364
+116959
+122862
+56580
+109631
+82895
+79666
+133474
+50579
+83473
+140028
+125999
+68225
+131345
+90797
+84914
+81915
+65369
+71230
+50379
+106385
+118503
+119640
+138540
+70678
+95881
+100282
+123060
+147368
+93030
+82553
+131271
+147675
+111126
+115183
+82956
+145698
+99261
+52768
+99207
+123551
+64738
+117275
+98136
+111592
+78576
+118613
+130351
+68567
+72356
+85608
+129414
+66521
+76924
+130449
\ No newline at end of file
diff --git a/day01/main.nim b/day01/main.nim
new file mode 100644
index 0000000..87e6154
--- /dev/null
+++ b/day01/main.nim
@@ -0,0 +1,24 @@
+import math, strutils
+
+proc fuelCalc(mass: int): int = 
+    floor(mass / 3).toInt - 2
+
+
+proc calcForFuel(fuelMass: int): int =
+    let required = fuelCalc(fuelMass)
+    if required <= 0:
+        return 0
+    else:
+        return required + calcForFuel(required)
+
+proc calc(mass: int): int =
+    var massFuel = fuelCalc(mass)
+    var fuelFuel = calcForFuel(massFuel)
+    return massFuel + fuelFuel
+
+var result = 0;
+var file = open("input.txt", fmRead);
+for line in file.lines:
+    result += calc(line.parseInt)
+
+echo result
\ No newline at end of file
diff --git a/day02/computer.nim b/day02/computer.nim
new file mode 100644
index 0000000..cd1daec
--- /dev/null
+++ b/day02/computer.nim
@@ -0,0 +1,69 @@
+import sequtils, strutils
+
+type
+  Program* = seq[int]
+  Input* = object
+    noun*: int
+    verb*: int
+  Computer* = ref object
+    source: Program     # Original program code without modifications
+    program*: Program   # The computers program in memory
+    ic*: int            # The instruction counter
+
+  StopExecution = object of Exception
+  ## This will be raised when the ending opcode is reached
+  
+proc set(cp: Computer, address, value: int): void = 
+  cp.program[address] = value
+
+proc get(cp: Computer, address: int): int = 
+  cp.program[address]
+
+proc add(cp: Computer, param1, param2, param3: int): void =
+  cp.set(param3, (cp.get(param1) + cp.get(param2)))
+
+proc mul(cp: Computer, param1, param2, param3: int): void =
+  cp.set(param3, (cp.get(param1) * cp.get(param2)))
+
+proc newComputer*(sourceFile: string): Computer =  
+  var file = readFile("input.txt");
+  file.stripLineEnd
+  let source = map(split(file, ','), parseInt)  
+  result = Computer(source: source, ic: 0)
+
+proc reset*(cp: Computer, input: Input): void =
+  ## Reset instruction pointer, program code and input values
+  cp.program = cp.source
+  cp.ic = 0
+  cp.set(1, input.noun)
+  cp.set(2, input.verb)
+
+proc process(cp: Computer): void = 
+  let opCode = cp.get(cp.ic)
+  if opCode == 99:   # End Execution
+    raise newException(StopExecution, "Program ended")
+  if opCode == 1:    # Addition
+    cp.add(cp.get(cp.ic+1), cp.get(cp.ic+2), cp.get(cp.ic+3))
+  if opCode == 2:    # Multiplication
+    cp.mul(cp.get(cp.ic+1), cp.get(cp.ic+2), cp.get(cp.ic+3))
+  cp.ic += 4
+
+proc run*(cp: Computer): int =
+  ## Runs the program loaded in memory until complete
+  try:
+    while true:
+      cp.process
+  except StopExecution:
+    return cp.get(0)
+  return -1   # Something went wrong
+
+proc findInputFor*(cp: Computer, target: int): Input =
+  ## Finds fitting inputs to produce the desired output
+  ## Stops at the first match
+  for noun in 0 .. 99:
+    for verb in 0 .. 99:
+      let input = Input(noun: noun, verb: verb)
+      cp.reset(input)
+      var output = cp.run
+      if output == target:
+        return input
\ No newline at end of file
diff --git a/day02/input.txt b/day02/input.txt
new file mode 100644
index 0000000..ec8a0ca
--- /dev/null
+++ b/day02/input.txt
@@ -0,0 +1 @@
+1,0,0,3,1,1,2,3,1,3,4,3,1,5,0,3,2,1,6,19,1,5,19,23,1,23,6,27,1,5,27,31,1,31,6,35,1,9,35,39,2,10,39,43,1,43,6,47,2,6,47,51,1,5,51,55,1,55,13,59,1,59,10,63,2,10,63,67,1,9,67,71,2,6,71,75,1,5,75,79,2,79,13,83,1,83,5,87,1,87,9,91,1,5,91,95,1,5,95,99,1,99,13,103,1,10,103,107,1,107,9,111,1,6,111,115,2,115,13,119,1,10,119,123,2,123,6,127,1,5,127,131,1,5,131,135,1,135,6,139,2,139,10,143,2,143,9,147,1,147,6,151,1,151,13,155,2,155,9,159,1,6,159,163,1,5,163,167,1,5,167,171,1,10,171,175,1,13,175,179,1,179,2,183,1,9,183,0,99,2,14,0,0
diff --git a/day02/main.nim b/day02/main.nim
new file mode 100644
index 0000000..a45b364
--- /dev/null
+++ b/day02/main.nim
@@ -0,0 +1,19 @@
+import computer
+
+proc solvePart1(): void = 
+  var 
+    cp = newComputer("input.txt")
+    input = Input(noun: 12, verb: 2)
+  cp.reset(input)
+  let result = cp.run
+  echo "Result for Part 1: ", result
+
+proc solvePart2(): void =
+  var 
+    target = 19690720
+    cp = newComputer("input.txt")
+    inputs = cp.findInputFor(target)
+  echo "result for Part 2: ", 100 * inputs.noun + inputs.verb
+
+solvePart1()
+solvePart2()  
\ No newline at end of file