two_thread_puzzle.kt

import kotlinx.coroutines.launch
import kotlinx.coroutines.newSingleThreadContext
import kotlinx.coroutines.runBlocking

// inspired by: https://dzone.com/articles/print-even-and-odd-numbers-using-two-threads-compl

// You can run this in a Kotlin REPL

fun main() = runBlocking {
  (1..100).forEach {
    val first = async(newSingleThreadContext("first")) {
      if (it % 2 == 1) println("$it ${Thread.currentThread().name}")
    }
    val second = async(newSingleThreadContext("second")) {
      if (it % 2 == 0) println("$it ${Thread.currentThread().name}")
    }
    first.await()
    second.await()
  }
}

main()