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Finish day10, part 1

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ktkk 2025-12-10 20:42:15 +00:00
parent ec4a937062
commit d68ac82e5d
1 changed files with 53 additions and 25 deletions
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78
src/days/day10.zig
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@ -3,14 +3,27 @@ const std = @import("std");
pub const title = "Day 10: Factory";
pub fn run(allocator: std.mem.Allocator) !void {
//const input = @embedFile("./input/day10.txt");
const input =
\\[.##.] (3) (1,3) (2) (2,3) (0,2) (0,1) {3,5,4,7}
\\[...#.] (0,2,3,4) (2,3) (0,4) (0,1,2) (1,2,3,4) {7,5,12,7,2}
\\[.###.#] (0,1,2,3,4) (0,3,4) (0,1,2,4,5) (1,2) {10,11,11,5,10,5}
;
const input = @embedFile("./input/day10.txt");
//const input =
// \\[.##.] (3) (1,3) (2) (2,3) (0,2) (0,1) {3,5,4,7}
// \\[...#.] (0,2,3,4) (2,3) (0,4) (0,1,2) (1,2,3,4) {7,5,12,7,2}
// \\[.###.#] (0,1,2,3,4) (0,3,4) (0,1,2,4,5) (1,2) {10,11,11,5,10,5}
// ;
//const input =
// \\[#...#] (1,3) (2,3,4) (0,2,3) (0,1,2) (2,3) {37,24,60,50,16}
// \\[##...#..] (0,1,3,5,6) (0,1,5) (4) (5,6) (0,4,7) (1,2,5) (3) {23,18,2,26,14,36,25,7}
// ;
var lines = std.mem.tokenizeScalar(u8, input, '\n');
var accumulator: usize = 0;
var light_states: std.ArrayList(std.bit_set.IntegerBitSet(Machine.MaxLightCount)) = .empty;
defer light_states.deinit(allocator);
var next_light_states: std.ArrayList(std.bit_set.IntegerBitSet(Machine.MaxLightCount)) = .empty;
defer next_light_states.deinit(allocator);
var i: usize = 0;
while (lines.next()) |line| {
defer i += 1;
@ -20,10 +33,41 @@ pub fn run(allocator: std.mem.Allocator) !void {
std.debug.print("{f}\n", .{machine});
const initial_lights_state: std.bit_set.IntegerBitSet(Machine.MaxLightCount) = .initEmpty();
const button_presses = machine.pressButtonSequences(initial_lights_state);
std.debug.print("machine {d} required {d} button presses", .{i, button_presses});
light_states.clearRetainingCapacity();
try light_states.append(allocator, .initEmpty());
var buttons_pressed: usize = 0;
outer: while (true) {
next_light_states.clearRetainingCapacity();
buttons_pressed += 1;
for (light_states.items) |state| {
for (machine.buttons) |button| {
const next_state = state.xorWith(button);
if (next_state.eql(machine.lights_goal)) {
break :outer;
}
try next_light_states.append(allocator, next_state);
}
}
light_states.clearRetainingCapacity();
try light_states.appendSlice(allocator, next_light_states.items);
}
std.debug.print("machine {d} requires {d} button presses\n", .{i, buttons_pressed});
accumulator += buttons_pressed;
}
var buffer: [64]u8 = undefined;
var stdout_writer = std.fs.File.stdout().writer(&buffer);
const stdout = &stdout_writer.interface;
try stdout.print("{d}\n", .{accumulator});
try stdout.flush();
}
const Machine = struct {
@ -83,21 +127,5 @@ const Machine = struct {
try w.print("({b})", .{button.mask});
}
}
pub fn pressButtonSequences(
self: Self,
initial_lights_state: std.bit_set.IntegerBitSet(MaxLightCount),
buttons_pressed: *usize,
) usize {
var button_presses: usize = 0;
for (self.buttons) |button| {
const result = initial_lights_state.xorWith(button);
if (result.mask == self.lights_goal.mask) {
return 1;
}
button_presses += self.pressButtonSequences(result);
}
return button_presses;
}
};