2021/1/first.nim

@@ -5,7 +5,7 @@ import
   strutils
 
 let input = adventofcode.getInput(2021, 1)
-let lines = input.splitLines()[0 .. ^2].mapIt(it.parseInt())
+let lines = input.splitLines().mapIt(it.parseInt())
 
 var depths = 0
 var prevResult = lines[0]

2021/1/second.nim

@@ -5,7 +5,7 @@ import
   strutils
 
 let input = adventofcode.getInput(2021, 1)
-let lines = input.splitLines()[0 .. ^2].mapIt(it.parseInt())
+let lines = input.splitLines().mapIt(it.parseInt())
 
 var depths = 0
 var prevSum = lines[0] + lines[1] + lines[2]

2021/2/both.nim

@@ -4,7 +4,7 @@ import
   strformat
 
 let input = adventofcode.getInput(2021, 2)
-let lines = input.splitLines()[0 .. ^2]
+let lines = input.splitLines()
 
 var horizontalPosition = 0
 var depth = 0

2021/3/first.nim

@@ -5,7 +5,7 @@ import
   strformat
 
 let input = adventofcode.getInput(2021, 3)
-let lines = input.splitLines()[0 .. ^2]
+let lines = input.splitLines()
 
 var gammaRateBinary = ""
 var epsilonRateBinary = ""

2021/3/second.nim

@@ -5,7 +5,7 @@ import
   strformat
 
 let input = adventofcode.getInput(2021, 3)
-let lines = input.splitLines()[0 .. ^2]
+let lines = input.splitLines()
 
 var oxygenGenRateValues = lines
 var co2ScrubberRateValues = lines

2021/4/first.nim

@@ -9,7 +9,7 @@ import
   x/board
   
 let input = adventofcode.getInput(2021, 4)
-let lines = input.splitLines()[0 .. ^2]
+let lines = input.splitLines()
 
 let drawn = lines[0].split(",").mapIt(it.parseInt())
 var currentlyDrawn: seq[int] = @[]

2021/4/second.nim

@@ -9,7 +9,7 @@ import
   x/board
   
 let input = adventofcode.getInput(2021, 4)
-let lines = input.splitLines()[0 .. ^2]
+let lines = input.splitLines()
 
 let drawn = lines[0].split(",").mapIt(it.parseInt())
 var currentlyDrawn: seq[int] = @[]

2021/5/both.nim

@@ -61,7 +61,7 @@ proc getPoints(v: HydrothermalVent): seq[Point] =
         )
   
 proc parseInput(input: string): seq[HydrothermalVent] = 
-  for line in input.splitLines()[0 .. ^2]:
+  for line in input.splitLines():
     let coords = line.split(" -> ").mapIt(it.split(",").mapIt(it.parseInt()))
     result.add HydrothermalVent(
       x1: coords[0][0], y1: coords[0][1], x2: coords[1][0], y2: coords[1][1] 

2021/6/both.nim

@@ -10,7 +10,6 @@ type
   Cycle = int
 
 let input = adventofcode.getInput(2021, 6)
-let inputLine = input.splitLines()[0]
 
 var days = 0
 var fishes: Table[Cycle, int]
@@ -18,7 +17,7 @@ for i in 0 .. 8:
   fishes[i] = 0
 
 proc parseInput() =
-  let cycles = inputLine.split(",").mapIt(it.parseInt())
+  let cycles = input.split(",").mapIt(it.parseInt())
   for cycle in cycles:
     fishes[cycle] += 1
 

2021/7/first.nim

@@ -0,0 +1,27 @@
+import
+  ../../adventofcode,
+  options,
+  sequtils,
+  strformat,
+  strutils
+  
+let input = adventofcode.getInput(2021, 7)[0 .. ^2]
+#let input = "16,1,2,0,4,2,7,1,2,14" # Example given
+let crabs = input.split(",").mapIt(it.parseInt())
+let minPos = min(crabs)
+let maxPos = max(crabs)
+
+var bestPosResult = none int
+var bestFuelResult = none int
+
+for pos in minPos .. maxPos:
+  var fuel = 0
+  for crab in crabs:
+    fuel += max(crab, pos) - min(crab, pos)
+    
+  if bestFuelResult.isNone() or fuel < bestFuelResult.get():
+    bestPosResult = some pos
+    bestFuelResult = some fuel
+  
+echo fmt"Position     : {bestPosResult.get()}"
+echo fmt"Fuel | Answer: {bestFuelResult.get()}"

2021/7/second.nim

@@ -0,0 +1,20 @@
+import
+  ../../adventofcode,
+  math,
+  sequtils,
+  strformat,
+  strutils
+  
+let input = adventofcode.getInput(2021, 7)
+#let input = "16,1,2,0,4,2,7,1,2,14" # Example given
+let crabs = input.split(",").mapIt(it.parseInt())
+
+let avg = toInt math.floor((math.sum crabs) / crabs.len())
+
+var fuel = 0
+for crab in crabs:
+  let distance = max(crab, avg) - min(crab, avg)
+  fuel += sum toSeq 1 .. distance
+    
+echo fmt"Position     : {avg}"
+echo fmt"Fuel | Answer: {fuel}"

2021/8/first.nim

@@ -0,0 +1,24 @@
+import
+  ../../adventofcode,
+  math,
+  sequtils,
+  strformat,
+  strutils,
+  tables
+
+let lines = adventofcode.getInput(2021, 8).splitLines()
+var decodedDigits = newTable[int, int]()
+for i in [2, 3, 4, 7]:
+  decodedDigits[i] = 0
+
+for line in lines:
+  let lineParts = line.split(" | ")
+
+  # We only consider output digits for now
+  let outputDigits = lineParts[1].split(" ")
+
+  for outputDigit in outputDigits:
+    if decodedDigits.hasKey outputDigit.len():
+      decodedDigits[outputDigit.len()] += 1
+
+echo fmt"Answer: {math.sum toSeq decodedDigits.values()}"

2021/9/first.nim

@@ -0,0 +1,38 @@
+import
+  ../../adventofcode,
+  math,
+  options,
+  sequtils,
+  strformat,
+  strutils
+  
+type
+  Grid = seq[seq[int]]
+  
+proc at(g: Grid; x, y: int): Option[int] =
+  try: result = some g[y][x]
+  except IndexDefect: discard
+  
+let input = adventofcode.getInput(2021, 9)
+let grid = Grid input.splitLines().mapIt(toSeq(it).mapIt(($it).parseInt()))
+
+var lowPoints = newSeq[int]()
+
+for y in 0 .. grid.high():
+  for x in 0 .. grid[y].high():
+    let p = grid.at(x, y).get()
+
+    let adjA = grid.at(x - 1, y)
+    if adjA.isSome() and p >= adjA.get(): continue
+    let adjB = grid.at(x, y - 1)
+    if adjB.isSome() and p >= adjB.get(): continue
+    let adjC = grid.at(x + 1, y)
+    if adjC.isSome() and p >= adjC.get(): continue
+    let adjD = grid.at(x, y + 1)
+    if adjD.isSome() and p >= adjD.get(): continue
+      
+    lowPoints.add p
+
+var riskLevels = lowPoints.mapIt(it + 1)
+
+echo fmt"Answer: {math.sum riskLevels}"

adventofcode.nim

@@ -1,13 +1,14 @@
 import
   httpclient,
   os,
-  strformat
+  strformat,
+  strutils
   
 proc getInput*(year, day: int): string =
   try:
     let input = readFile(getCurrentDir() / "input.txt")
     
-    return input
+    return input.strip(chars = {'\n'})
   except IOError:
     echo "adventofcode> Missing input.txt. Downloading..."
     let session = os.getEnv("SESSION")
@@ -22,4 +23,4 @@ proc getInput*(year, day: int): string =
     
     writeFile(getCurrentDir() / "input.txt", input)
     
-    return input
+    return input.strip(chars = {'\n'})