123 lines
2.9 KiB
Zig
123 lines
2.9 KiB
Zig
const std = @import("std");
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const intcode = @import("intcode");
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const boardX = 1024;
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const boardY = 1024;
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const Point = struct {
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x: usize,
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y: usize,
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fn go(self: Point, d: Compass) Point {
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var out = Point{.x = self.x, .y = self.y};
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switch (d) {
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.North => out.y -= 1,
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.East => out.x += 1,
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.South => out.y += 1,
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.West => out.x -= 1,
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}
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return out;
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}
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};
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const Compass = enum(u8) {
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North = 0,
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East = 1,
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South = 2,
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West = 3,
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fn turn(self: Compass, direction: intcode.Word) Compass {
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return switch (direction) {
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0 => self.widdershins(),
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1 => self.deasil(),
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else => unreachable,
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};
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}
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fn deasil(self: Compass) Compass {
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if (self == .West) return .North;
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return @intToEnum(Compass, @enumToInt(self)+1);
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}
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fn widdershins(self: Compass) Compass {
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if (self == .North) return .West;
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return @intToEnum(Compass, @enumToInt(self)-1);
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}
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};
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const Colour = enum(u8) {
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Black = 0,
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White = 1,
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};
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const Cell = struct {
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colour: Colour,
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touched: bool = false,
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};
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const Board = [boardY][boardX]Cell;
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fn runMachine(m: *intcode.Machine) void {
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if (m.run()) {} else |err| {
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std.debug.warn("Machine failed to run successfully: {}\n", err);
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}
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}
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pub fn main() anyerror!void {
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var arena = std.heap.ArenaAllocator.init(std.heap.page_allocator);
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defer arena.deinit();
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const alloc = &arena.allocator;
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var board: Board = undefined;
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for (board) |*row| {
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for (row) |*cell| {
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cell.* = Cell{.colour = .Black, .touched = false};
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}
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}
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// Current state of the robot
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var pos = Point{.x = boardX / 2, .y = boardY / 2};
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var direction = Compass.North;
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var program = try intcode.loadFromStdIn(alloc);
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var machine = try intcode.Machine.init(alloc, program);
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var robot = try std.Thread.spawn(&machine, runMachine);
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// Robot event loop
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while (!machine.halted) {
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// Feed it the colour at its current position
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try machine.writeToInput(@enumToInt(board[pos.y][pos.x].colour));
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// Read back instructions
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var paintColour = try machine.readFromOutput();
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var turnDirection = try machine.readFromOutput();
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// Paint
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board[pos.y][pos.x].colour = @intToEnum(Colour, @intCast(u8, paintColour));
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board[pos.y][pos.x].touched = true;
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// Turn in the specified direction and move forward one square
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direction = direction.turn(turnDirection);
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pos = pos.go(direction);
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// Ugh. Give the other thread some time to decide to halt or not.
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std.time.sleep(1000);
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}
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robot.wait();
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var touched: usize = 0;
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for (board) |row| {
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for (row) |cell| {
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if (cell.touched) touched += 1;
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}
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}
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std.debug.warn("Day 11, Part 1: {}\n", touched);
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}
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