Flippies

1billion_flips_histogram.txt

Programmatic finished in 687498 ms
Programmatic finished in 1152935 ms
Ran calculations 1000000000 times. Results:

|-----------------------------------|
| Flips | Programmatic | Mathy      |
|-----------------------------------|
| 0     | 499999527    | 499991146  |
| 1     | 249993072    | 249998627  |
| 2     | 125001055    | 125011612  |
| 3     | 62492746     | 62498907   |
| 4     | 31256879     | 31251061   |
| 5     | 15627678     | 15629935   |
| 6     | 7814956      | 7810012    |
| 7     | 3905760      | 3904077    |
| 8     | 1953173      | 1950435    |
| 9     | 977938       | 977145     |
| 10    | 488813       | 488830     |
| 11    | 243709       | 244128     |
| 12    | 122460       | 122031     |
| 13    | 61021        | 61414      |
| 14    | 30625        | 30170      |
| 15    | 15301        | 15196      |
| 16    | 7729         | 7782       |
| 17    | 3838         | 3812       |
| 18    | 1938         | 1881       |
| 19    | 965          | 913        |
| 20    | 476          | 467        |
| 21    | 252          | 246        |
| 22    | 119          | 148        |
| 23    | 52           | 75         |
| 24    | 55           | 33         |
| 25    | 36           | 12         |
| 26    | 9            | 38         |
| 27    | 2            | 27         |
| 28    | 28           | 1          |
| 29    | 0            | 29         |
| 31    | 0            | 31         |
| 32    | 32           | 0          |
|-----------------------------------|

flips_histogram.txt

➜  ~ groovy programmatic_flip.groovy
Programmatic finished in 20046 ms
Mathy finished in 66939 ms
Ran calculations 100000000 times. Results:

|-----------------------------------|
| Flips | Programmatic | Mathy      |
|-----------------------------------|
| 0     | 49995423     | 49995644   |
| 1     | 25003918     | 25003168   |
| 2     | 12499532     | 12501003   |
| 3     | 6249696      | 6250883    |
| 4     | 3126074      | 3125518    |
| 5     | 1562236      | 1562134    |
| 6     | 782222       | 780953     |
| 7     | 390292       | 391219     |
| 8     | 195191       | 194695     |
| 9     | 97552        | 97459      |
| 10    | 49032        | 48510      |
| 11    | 24383        | 24274      |
| 12    | 12433        | 12193      |
| 13    | 6039         | 6206       |
| 14    | 3016         | 3128       |
| 15    | 1589         | 1511       |
| 16    | 730          | 766        |
| 17    | 359          | 369        |
| 18    | 191          | 223        |
| 19    | 105          | 101        |
| 20    | 71           | 49         |
| 21    | 51           | 21         |
| 22    | 32           | 11         |
| 23    | 34           | 2          |
| 24    | 1            | 26         |
| 25    | 25           | 1          |
| 26    | 2            | 27         |
| 28    | 0            | 28         |
|-----------------------------------|

programmatic_flip.groovy

@Grapes(
    @Grab(group='com.google.guava', module='guava', version='30.0-jre')
)

import java.util.Random
import java.util.concurrent.ConcurrentHashMap
import java.util.concurrent.CountDownLatch
import java.util.concurrent.TimeUnit
import com.google.common.base.Stopwatch
import groovy.transform.Canonical

def totalsHistogram = new ConcurrentHashMap()
def occurrences = 100_000_000
def latch = new CountDownLatch(2)

@Canonical
class Totals {

  def programmatic = 0
  def mathy = 0
}

Thread.start {

  def stopwatch = Stopwatch.createStarted()
  def random = new Random()
  occurrences.times {

    def flip = true
    def count = 0

    while(flip) {
      if (random.nextBoolean()) {
        count++
      } else {
        break
      }
    }

    if (totalsHistogram.containsKey(count)) {
      ++totalsHistogram.get(count).programmatic
    } else {
      totalsHistogram.put(count, new Totals(programmatic: count))
    }
  }
  println "Programmatic finished in ${stopwatch.elapsed(TimeUnit.MILLISECONDS)} ms"
  latch.countDown()
}

Thread.start {

  def stopwatch = Stopwatch.createStarted()
  def random = new Random()
  def pointFiveLN = Math.log(0.5)

  occurrences.times {

    count = (Math.log(random.nextDouble()) / pointFiveLN) as Integer

    if (totalsHistogram.containsKey(count)) {
      ++totalsHistogram.get(count).mathy
    } else {
      totalsHistogram.put(count, new Totals(mathy: count))
    }
  }
  println "Mathy finished in ${stopwatch.elapsed(TimeUnit.MILLISECONDS)} ms"
  latch.countDown()
}

latch.await()

println "Ran calculations ${occurrences} times. Results:"
println ''
println '|-----------------------------------|'
println '| Flips | Programmatic | Mathy      |'
println '|-----------------------------------|'

def formatOutput = '| %-5s | %-12s | %-10s |%n'

totalsHistogram.keySet().sort().each { key ->
  def totals = totalsHistogram.get(key)
  System.out.format(formatOutput, key, totals.programmatic, totals.mathy)
}

println "|-----------------------------------|"