e042.swift

#!/usr/bin/swift
import Foundation

func timeit(_ f:() -> ()) {
	let s = Date()
	f()
	let e = String(format:"time: %.4fms", s.timeIntervalSinceNow * -1000)
	print(e)
}

timeit{
	guard let url = URL(string: "http://euler.synap.co.kr/files/words.txt"),
	     let contents = try? String(contentsOf: url)
    else { return }

	func wordPoint(_ s: Substring) -> Int {
		let x = s.trimmingCharacters(in: CharacterSet(charactersIn: "\""))
			.utf8.flatMap{ Int($0) - 64 }
			.reduce(0, +)
		return x
	}

	let make_t:(Int) -> Int = { $0 * ($0 + 1) / 2 }
	let ts = Set((1...1000).map(make_t))

	let result = contents.split(separator:",")
				.map(wordPoint) .filter{ ts.contains($0) }.count
	print(result)
}