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const ArenaAllocator = std.heap.ArenaAllocator;
const AutoHashMap = std.AutoHashMap;
const min = std.math.min;
const page_allocator = std.heap.page_allocator;
const parseUnsigned = std.fmt.parseUnsigned;
const print = std.debug.print;
const split = std.mem.split;
const std = @import("std");
const tokenize = std.mem.tokenize;
const Dot = struct { x: u12, y: u12 };
inline fn mirror(a: u12, m: u12) u12 { return min(a, m + m - a); }
fn foldX(d: Dot, m: u12) Dot { return .{ .x = mirror(d.x, m), .y = d.y }; }
fn foldY(d: Dot, m: u12) Dot { return .{ .x = d.x, .y = mirror(d.y, m) }; }
pub fn main() !void {
var arena = ArenaAllocator.init(page_allocator);
defer arena.deinit();
var map = AutoHashMap(Dot, void).init(&arena.allocator);
defer map.deinit();
defer print("{}\n", .{ map.count() });
var input = split(@embedFile("input"), "\n\n");
var dots = tokenize(input.next().?, "\n");
var folds = tokenize(input.next().?, "\n");
const instruction = folds.next().?;
while (dots.next()) |line| {
var coord = tokenize(line, ",");
const dot = Dot{ .x = try parseUnsigned(u12, coord.next().?, 10),
.y = try parseUnsigned(u12, coord.next().?, 10) };
try map.put(switch (instruction[11]) {
'x' => foldX, 'y' => foldY,
else => unreachable,
} (dot, try parseUnsigned(u12, instruction[13..], 10)), {});
}
}
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