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const std = @import("std");
const mecha = @import("mecha");
const print = std.debug.print;
pub fn solve(part: []u8, buffer: []u8, allocator: std.mem.Allocator) !void {
if (std.mem.eql(u8, part, "1")) {
try part1(buffer, allocator);
} else {
try part2(buffer, allocator);
}
}
fn part1(buffer: []const u8, allocator: std.mem.Allocator) !void {
const mul = mecha.combine(.{ mecha.string("mul(").discard(), mecha.int(usize, .{}), mecha.ascii.char(',').discard(), mecha.int(usize, .{}), mecha.ascii.char(')').discard() });
var sum: usize = 0;
var rest = buffer;
while (rest.len > 0) {
const result = mul.parse(allocator, rest) catch {
rest = rest[1..];
continue;
};
sum += result.value[0] * result.value[1];
rest = result.rest;
}
print("{d}", .{sum});
}
// UGLY
fn part2(buffer: []const u8, allocator: std.mem.Allocator) !void {
const mul = mecha.combine(.{ mecha.string("mul(").discard(), mecha.int(usize, .{}), mecha.ascii.char(',').discard(), mecha.int(usize, .{}), mecha.ascii.char(')').discard() });
const dont = mecha.string("don't()");
const do = mecha.string("do()");
var sum: usize = 0;
var rest = buffer;
var disabled = false;
while (rest.len > 0) {
if (disabled) {
_ = do.parse(allocator, rest) catch {
rest = rest[1..];
continue;
};
disabled = false;
} else {
const result = mul.parse(allocator, rest) catch {
const result = dont.parse(allocator, rest) catch {
rest = rest[1..];
continue;
};
rest = result.rest;
disabled = true;
continue;
};
sum += result.value[0] * result.value[1];
rest = result.rest;
}
}
print("{d}", .{sum});
}
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