add day 10

3 files changed, 214 insertions, 0 deletions

diff --git a/day_10.zig b/day_10.zig
new file mode 100644
index 0000000..b8cacc7
--- /dev/null
+++ b/day_10.zig
@@ -0,0 +1,73 @@
+const std = @import("std");
+const Result = @import("util/aoc.zig").Result;
+
+pub fn puzzle_1(input: []const u8) Result {
+    var cycle: u16 = 1;
+    var register: i16 = 1;
+    var sum: u16 = 0;
+
+    var iter = std.mem.split(u8, input, "\n");
+    while (iter.next()) |line| {
+        if (cycle % 40 == 20) sum += cycle * @intCast(u16, register);
+        cycle += 1;
+
+        if (line[0] != 'a') continue;
+
+        const n = std.fmt.parseInt(i16, line[5..], 0) catch unreachable;
+
+        if (cycle % 40 == 20) sum += cycle * @intCast(u16, register);
+        cycle += 1;
+
+        register += n;
+    }
+
+    return .{ .int = sum };
+}
+
+fn crt(cycle: u16, register: i16, screen: *[6][40]bool) void {
+    const pixel_id = (cycle - 1) % 240;
+    const pixel_row = pixel_id / 40;
+    const pixel_col = pixel_id % 40;
+
+    if (pixel_col == register or pixel_col == (register - 1) or pixel_col == (register + 1)) {
+        screen.*[pixel_row][pixel_col] = true;
+    } else {
+        screen.*[pixel_row][pixel_col] = false;
+    }
+}
+
+pub fn puzzle_2(input: []const u8) Result {
+    var cycle: u16 = 1;
+    var register: i16 = 1;
+    var screen = [_][40]bool{[_]bool{false} ** 40} ** 6;
+
+    var iter = std.mem.split(u8, input, "\n");
+    while (iter.next()) |line| {
+        crt(cycle, register, &screen);
+        cycle += 1;
+        crt(cycle, register, &screen);
+        if (line[0] != 'a') continue;
+        const n = std.fmt.parseInt(i16, line[5..], 0) catch unreachable;
+        cycle += 1;
+        crt(cycle, register, &screen);
+        register += n;
+    }
+
+    //for (screen) |row| {
+    //for (row) |pixel| {
+    //if (pixel) {
+    //std.debug.print("@", .{});
+    //} else {
+    //std.debug.print(" ", .{});
+    //}
+    //}
+    //std.debug.print("\n", .{});
+    //}
+
+    var r: usize = 0;
+    for (screen) |row, x| {
+        for (row) |pixel, y| r += y * x * @boolToInt(pixel);
+    }
+
+    return .{ .int = @intCast(i32, r) };
+}
diff --git a/inputs/day_10 b/inputs/day_10
new file mode 100644
index 0000000..5fab235
--- /dev/null
+++ b/inputs/day_10
@@ -0,0 +1,140 @@
+noop
+addx 25
+addx -5
+addx -14
+addx 4
+noop
+addx 2
+addx 3
+noop
+noop
+noop
+noop
+addx 3
+addx 5
+addx 2
+noop
+noop
+addx 5
+noop
+noop
+noop
+addx 1
+addx 2
+addx 5
+addx -40
+addx 5
+noop
+addx 26
+addx -20
+addx -3
+addx 2
+noop
+addx -4
+addx 9
+addx 5
+addx 2
+addx 11
+addx -10
+addx 2
+addx 5
+addx 2
+addx 5
+noop
+noop
+noop
+addx -31
+addx 32
+addx -37
+addx 1
+addx 8
+addx 13
+addx -15
+addx 4
+noop
+addx 5
+noop
+addx 3
+addx -2
+addx 4
+addx 1
+addx 4
+addx -14
+addx 15
+addx 4
+noop
+noop
+noop
+addx 3
+addx 5
+addx -40
+noop
+addx 5
+addx 8
+addx -3
+noop
+addx 2
+addx 9
+addx -4
+noop
+noop
+noop
+noop
+addx 5
+addx -9
+addx 10
+addx 4
+noop
+noop
+addx 5
+addx -19
+addx 24
+addx -2
+addx 5
+addx -40
+addx 22
+addx -19
+addx 2
+addx 5
+addx 2
+addx 5
+noop
+noop
+addx -2
+addx 2
+addx 5
+addx 3
+noop
+addx 2
+addx 2
+addx 3
+addx -2
+addx 10
+addx -3
+addx 3
+noop
+addx -40
+addx 2
+addx 11
+addx -5
+addx -1
+noop
+addx 3
+addx 7
+noop
+addx -2
+addx 5
+addx 2
+addx 3
+noop
+addx 2
+addx 6
+addx -5
+addx 2
+addx -18
+addx 26
+addx -1
+noop
+noop
+noop
+noop
diff --git a/main.zig b/main.zig
index 5108467..8b15132 100644
--- a/main.zig
+++ b/main.zig
@@ -15,6 +15,7 @@ const t = [_]struct {
     .{ .day = @import("day_07.zig"), .input = @embedFile("inputs/day_07"), .expect = &[_]Result{ .{ .int = 1427048 }, .{ .int = 2940614 } } },
     .{ .day = @import("day_08.zig"), .input = @embedFile("inputs/day_08"), .expect = &[_]Result{ .{ .int = 1859 }, .{ .int = 332640 } } },
     .{ .day = @import("day_09.zig"), .input = @embedFile("inputs/day_09"), .expect = &[_]Result{ .{ .int = 6087 }, .{ .int = 2493 } } },
+    .{ .day = @import("day_10.zig"), .input = @embedFile("inputs/day_10"), .expect = &[_]Result{ .{ .int = 14620 }, .{ .int = 4210 } } },
 };
 
 pub fn main() !void {