1 files changed, 78 insertions, 0 deletions
diff --git a/day_06.zig b/day_06.zig
new file mode 100644
index 0000000..38aeddd
--- /dev/null
+++ b/day_06.zig
@@ -0,0 +1,78 @@
+const std = @import("std");
+const Result = @import("util/aoc.zig").Result;
+
+pub fn puzzle_1(input: []const u8) Result {
+    var iter = std.mem.split(u8, input, "\n");
+
+    var i: usize = 0;
+    mainLoop: while (iter.next()) |line| {
+        var buf = std.mem.zeroes([4]u32);
+        var buf_idx: usize = 0;
+        for (line) |c, idx| {
+            if (buf_idx > 3) buf_idx = 0;
+            buf[buf_idx] = @as(u32, 1) << @intCast(u5, c - 97); // 97 == 'a'
+            buf_idx += 1;
+            if (@popCount(buf[0] | buf[1] | buf[2] | buf[3]) == 4) {
+                i = idx + 1;
+                break :mainLoop;
+            }
+        }
+    }
+
+    return .{ .int = @intCast(i32, i) };
+}
+
+pub fn puzzle_2(input: []const u8) Result {
+    var iter = std.mem.split(u8, input, "\n");
+
+    var i: usize = 0;
+    mainLoop: while (iter.next()) |line| {
+        var buf = std.mem.zeroes([14]u32);
+        var buf_idx: usize = 0;
+        for (line) |c, idx| {
+            if (buf_idx > 13) buf_idx = 0;
+            buf[buf_idx] = @as(u32, 1) << @intCast(u5, c - 97); // 97 == 'a'
+            buf_idx += 1;
+
+            const hammer: u32 = blk: {
+                var hidx: usize = 0;
+                var tmp: u32 = 0;
+                while (hidx < 14) : (hidx += 1) tmp |= buf[hidx];
+                break :blk tmp;
+            };
+
+            if (@popCount(hammer) == 14) {
+                i = idx + 1;
+                break :mainLoop;
+            }
+        }
+    }
+
+    return .{ .int = @intCast(i32, i) };
+}
+
+//pub fn puzzle_2(input: []const u8) Result {
+//var iter = std.mem.split(u8, input, "\n");
+
+//var count: u16 = 0;
+//mainLoop: while (true) {
+//var parts = std.mem.zeroes([3]u64);
+
+//for (parts) |*p| {
+//const line = iter.next() orelse break :mainLoop;
+//for (line) |_, i| {
+//p.* |= @as(u64, 1) << @intCast(u6, line[i] - 65);
+//}
+//}
+
+//count += char_to_priority(@intCast(u8, 65 + 63) - @clz(parts[0] & parts[1] & parts[2]));
+//}
+
+//return .{ .int = count };
+//}
+
+//fn char_to_priority(char: u8) u8 {
+//if (char >= 65 and char <= 90)
+//return char - 38;
+//return char - 96;
+//}