From 06eb7c1f08b26d14577731b98742adc44142d7b8 Mon Sep 17 00:00:00 2001
From: dece <shgck@pistache.land>
Date: Mon, 6 Dec 2021 12:50:27 +0100
Subject: [PATCH] Day 6

---
 2021/day6.py | 35 +++++++++++++++++++++++++++++++++++
 1 file changed, 35 insertions(+)
 create mode 100644 2021/day6.py

diff --git a/2021/day6.py b/2021/day6.py
new file mode 100644
index 0000000..3399353
--- /dev/null
+++ b/2021/day6.py
@@ -0,0 +1,35 @@
+import sys
+
+
+def main():
+    lines = [line.rstrip() for line in sys.stdin]
+    data = {k: 0 for k in range(1, 6)}
+    for n in map(int, lines[0].split(",")):
+        data[n] += 1
+
+    # Part 1
+    for _ in range(80):
+        data = step(data)
+    print(sum(data.values()))
+
+    # Part 2
+    for _ in range(256 - 80):
+        data = step(data)
+    print(sum(data.values()))
+
+
+def step(data):
+    next_data = {k: 0 for k in range(1, 9)}
+    for k, v in data.items():
+        if v == 0:
+            continue
+        if k == 0:
+            next_data[6] += v
+            next_data[8] += v
+        else:
+            next_data[k - 1] = v
+    return next_data
+
+
+if __name__ == "__main__":
+    main()