[aoc] Add day 6

2 files changed, 31 insertions, 0 deletions

diff --git a/aoc/2021/06/part-one.py b/aoc/2021/06/part-one.py
new file mode 100644
index 0000000..f1ad2fb
--- /dev/null
+++ b/aoc/2021/06/part-one.py
@@ -0,0 +1,9 @@
+from collections import deque
+from sys import stdin
+
+timer = deque([0] * 9)
+for i in map(int, stdin.read().strip().split(',')): timer[i] += 1
+for i in range(80):
+    timer.rotate(-1)
+    timer[6] += timer[-1]
+print(sum(timer))
diff --git a/aoc/2021/06/part-two.zig b/aoc/2021/06/part-two.zig
new file mode 100644
index 0000000..72bf877
--- /dev/null
+++ b/aoc/2021/06/part-two.zig
@@ -0,0 +1,22 @@
+const parseUnsigned = std.fmt.parseUnsigned;
+const print = std.debug.print;
+const rotate = std.mem.rotate;
+const std = @import("std");
+const tokenize = std.mem.tokenize;
+
+const input = @embedFile("input");
+
+pub fn main() !void {
+    var timer = [_]usize{ 0 } ** 9;
+    defer print("{}\n", .{ @reduce(.Add, @as(@Vector(9, usize), timer)) });
+
+    var list = tokenize(input[0..input.len-1], ",");
+    while (list.next()) |i|
+        timer[try parseUnsigned(usize, i, 10)] += 1;
+
+    var i: usize = 0;
+    while (i < 256) : (i += 1) {
+        rotate(usize, timer[0..], 1);
+        timer[6] += timer[8];
+    }
+}