2023/03/first.nim

@@ -0,0 +1,44 @@
+import
+  std/sequtils,
+  std/strformat,
+  std/strutils
+
+import
+  ../../adventofcode
+
+let input = adventofcode.getInput()
+var sum = 0
+
+var schematic: seq[seq[char]] = input.splitLines().mapIt(toSeq it)
+
+for y in 0 .. schematic.high():
+  var numStr = ""
+  for x in 0 .. schematic[y].high():
+    block wholeChara:
+      let chara = schematic[y][x]
+      if not chara.isDigit():
+        numStr.reset()
+        continue
+      numStr &= chara
+
+      if x == schematic[y].high() or not schematic[y][x + 1].isDigit():
+        # x = end index
+        var adjacentPositions: seq[(int, int)] = @[]
+        for i in 0 .. numStr.high():
+          # up, down
+          adjacentPositions.add (x - numStr.high() + i, y - 1)
+          adjacentPositions.add (x - numStr.high() + i, y + 1)
+        for dy in -1 .. 1:
+          # left, right
+          adjacentPositions.add (x - numStr.high() - 1, y + dy)
+          adjacentPositions.add (x + 1, y + dy)
+
+        for pos in adjacentPositions:
+          if pos[0] < 0 or pos[0] > schematic[y].high(): continue
+          if pos[1] < 0 or pos[1] > schematic.high(): continue
+          let charaToCheck = schematic[pos[1]][pos[0]]
+          if not charaToCheck.isDigit() and charaToCheck != '.':
+            sum += numStr.parseInt()
+            break wholeChara
+
+echo fmt"Answer: {sum}"