Update for a more general solution.

day-06/solution.py

@@ -0,0 +1,77 @@
+from __future__ import print_function
+import fileinput
+import re
+import sys
+
+def compact(lightList):
+    last = None
+    newList = []
+    for streak in sorted(lightList):
+        if last is not None:
+            if streak[2] == last[2]:
+                # Repeating state, merge
+                last = (last[0], streak[1], last[2])
+                continue
+            else:
+                newList.append(last)
+
+        last = streak
+
+    newList.append(last)
+
+    return newList
+
+def updateState(sliceList, yStart, yEnd, updateFnc):
+    newList = []
+    for start, end, state in lights[x]:
+        if not start <= yStart  <= end and not yStart <= start <= yEnd:
+            # Block not in range, skip
+            newList.append((start, end, state))
+            continue
+
+        if start < yStart:
+            # Split the block at the start
+            newList.append((start, yStart - 1, state))
+            start = yStart
+
+        if end > yEnd:
+            # Split the block at the end
+            newList.append((yEnd + 1, end, state))
+            end = yEnd
+
+        newList.append((start, end, updateFnc(state)))
+
+    return compact(newList)
+
+def colsum(lightList):
+    return sum(int(state) * (stop - start + 1) for start, stop, state in lightList)
+
+def getPart1Update(command):
+    if "toggle" in command:
+        return lambda x: not x
+    elif "on" in command:
+        return lambda _: True
+    else:
+        return lambda _: False
+
+lights = []
+for x in range(1000):
+    lights.append([(0, 999, False)])
+
+for line in fileinput.input():
+    match = re.search(r"^(toggle|turn (on|off)) (\d+),(\d+) through (\d+),(\d+)$", line)
+
+    xStart = int(match.group(3))
+    yStart = int(match.group(4))
+
+    xEnd = int(match.group(5))
+    yEnd = int(match.group(6))
+
+    command = match.group(1)
+
+    for x in range(xStart, xEnd + 1):
+        lights[x] = updateState(lights[x], yStart, yEnd, getPart1Update(command))
+
+total = sum(colsum(x) for x in lights)
+
+print(total)