From a0ac7b9a1d5ca940c037fe1f1d9d96b3a4d8f822 Mon Sep 17 00:00:00 2001
From: daviddoji <daviddoji@pm.me>
Date: Fri, 4 Mar 2022 12:23:28 +0100
Subject: [PATCH] Solution to problem 6 part 1 in Python

---
 src/Year_2015/P6.py | 94 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 94 insertions(+)
 create mode 100644 src/Year_2015/P6.py

diff --git a/src/Year_2015/P6.py b/src/Year_2015/P6.py
new file mode 100644
index 0000000..e15a3ff
--- /dev/null
+++ b/src/Year_2015/P6.py
@@ -0,0 +1,94 @@
+# --- Day 6: Probably a Fire Hazard ---
+
+# Because your neighbors keep defeating you in the holiday house decorating
+# contest year after year, you've decided to deploy one million lights in a
+# 1000x1000 grid.
+
+# Furthermore, because you've been especially nice this year, Santa has mailed
+# you instructions on how to display the ideal lighting configuration.
+
+# Lights in your grid are numbered from 0 to 999 in each direction; the lights
+# at each corner are at 0,0, 0,999, 999,999, and 999,0. The instructions
+# include whether to turn on, turn off, or toggle various inclusive ranges
+# given as coordinate pairs. Each coordinate pair represents opposite corners
+# of a rectangle, inclusive; a coordinate pair like 0,0 through 2,2 therefore
+# refers to 9 lights in a 3x3 square. The lights all start turned off.
+
+# To defeat your neighbors this year, all you have to do is set up your lights
+# by doing the instructions Santa sent you in order.
+
+# For example:
+
+#     turn on 0,0 through 999,999 would turn on (or leave on) every light.
+#     toggle 0,0 through 999,0 would toggle the first line of 1000 lights,
+# turning off the ones that were on, and turning on the ones that were off.
+#     turn off 499,499 through 500,500 would turn off (or leave off) the
+# middle four lights.
+
+# After following the instructions, how many lights are lit?
+
+from collections import defaultdict
+
+with open("files/P6.txt") as f:
+    instructions = [line for line in f.read().strip().split("\n")]
+
+# print(instructions)
+
+
+def get_coordinates(s: str) -> tuple[str, int, int, int, int]:
+    if s.startswith(("turn off", "turn on")):
+        _s = s.split()
+        action = _s[1]
+        x1, x2 = _s[2].split(",")
+        y1, y2 = _s[4].split(",")
+        return action, int(x1), int(x2), int(y1), int(y2)
+    if s.startswith("toggle"):
+        _s = s.split()
+        action = _s[0]
+        x1, x2 = _s[1].split(",")
+        y1, y2 = _s[3].split(",")
+        return action, int(x1), int(x2), int(y1), int(y2)
+
+
+def apply_action(
+    action: str,
+    coords: list[int],
+    grid: dict[tuple[int, int], int],
+) -> dict[tuple[int, int], int]:
+    if action == "off":
+        for x in range(coords[0], coords[2] + 1):
+            for y in range(coords[1], coords[3] + 1):
+                grid[x, y] = 0
+        return grid
+    elif action == "on":
+        for x in range(coords[0], coords[2] + 1):
+            for y in range(coords[1], coords[3] + 1):
+                grid[x, y] = 1
+        return grid
+    elif action == "toggle":
+        for x in range(coords[0], coords[2] + 1):
+            for y in range(coords[1], coords[3] + 1):
+                if grid[x, y] == 1:
+                    grid[x, y] = 0
+                elif grid[x, y] == 0:
+                    grid[x, y] = 1
+        return grid
+
+
+def part_1():
+    # Initially, all lights are off("0")
+    grid = defaultdict(int)
+    for x in range(1000):
+        for y in range(1000):
+            grid[x, y] = 0
+
+    for instruction in instructions:
+        action, *coords = get_coordinates(instruction)
+        grid = apply_action(action, coords, grid)
+
+    lit = sum(1 for value in grid.values() if value == 1)
+    print(f"There are {lit} ligths lit")
+
+
+if __name__ == "__main__":
+    part_1()