Add day 4, 5, and 6

Signed-off-by: Alek Ratzloff <alekratz@gmail.com>

day06/day06.py

@@ -0,0 +1,47 @@
+#!/usr/bin/env python3
+import sys
+from typing import Sequence
+from copy import deepcopy
+
+
+def part1(fish: Sequence[int], count: int):
+    for i in range(count):
+        new = []
+        for f in fish:
+            if f == 0:
+                new += [8]
+                f = 7
+            f -= 1
+            new += [f]
+        fish = new
+    print(len(fish))
+
+
+def part2(init: Sequence[int], count: int):
+    # This is a mapping for the number of fish by index, 0-8
+    fish = [0] * 9
+    for i in init:
+        fish[i] += 1
+    # Go through each day, rotating everything to the left
+    for _ in range(count):
+        zeroes = fish[0]
+        # rotate
+        for i in range(1, len(fish)):
+            fish[i - 1] = fish[i]
+        # position 8
+        fish[len(fish) - 1] = zeroes
+        # position 6
+        fish[len(fish) - 3] += zeroes
+    print(sum(fish))
+
+
+fish = [int(state) for state in sys.stdin.readline().strip().split(",") if state]
+
+print("Part 1 (80 days)")
+# part1(fish, 80)
+# Part 2 function does the same thing except much faster
+part2(fish, 80)
+print(len(fish))
+
+print("Part 2 (256 days)")
+part2(fish, 256)