day25.swift

import Foundation

let args = CommandLine.arguments
if args.count == 1 {
  print("Usage: \(args[0]) <path to input>")
  exit(1)
}

let rawInput = try String(contentsOfFile: args[1], encoding: .utf8)
let schematics = rawInput.split(separator: "\n\n")
  .map { $0.replacing("\n", with: "") }
  .map { $0.reduce(UInt64(0)) { ($0 << 1) | ($1 == "#" ? 1 : 0) } }

let part1 = schematics
  .enumerated()
  .map { (i, s1) in schematics.dropFirst(i + 1).filter { s2 in s1 & s2 == 0 }.count }
  .reduce(0, +)

print("Part 1: \(part1)")