Data commit

Task/Langtons-ant/Nim/langtons-ant.nim

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+import strutils, sequtils
+
+type
+  Direction = enum up, right, down, left
+  Color = enum white, black
+
+const
+  width = 75
+  height = 52
+  maxSteps = 12_000
+
+var
+  m: array[height, array[width, Color]]
+  dir = up
+  x = width div 2
+  y = height div 2
+
+var i = 0
+while i < maxSteps and x in 0 ..< width and y in 0 ..< height:
+  let turn = m[y][x] == black
+  m[y][x] = if m[y][x] == black: white else: black
+
+  dir = Direction((4 + int(dir) + (if turn: 1 else: -1)) mod 4)
+  case dir
+  of up:    dec y
+  of right: dec x
+  of down:  inc y
+  of left:  inc x
+
+  inc i
+
+for row in m:
+  echo map(row, proc(x: Color): string =
+    if x == white: "." else: "#").join("")