how many valid CPFs are there?

main.go

package main

import (
	"fmt"
	"runtime"
)

type CPF []int

func NewCPF(cpf int64) CPF {
	digits := make([]int, 11)
	index := 10

	for cpf > 0 {
		digits[index] = int(cpf % 10)
		cpf = cpf / 10

		index--
	}

	return digits
}

func (cpf CPF) Valid() bool {
	add := 0

	if cpf.allDigitsAreEqual() {
		return false
	}

	for i := 0; i < 9; i++ {
		add += cpf[i] * (10 - i)
	}

	rev := 11 - (add % 11)
	if rev > 9 {
		rev = 0
	}

	if rev != cpf[9] {
		return false
	}

	add = 0
	for i := 0; i < 10; i++ {
		add += cpf[i] * (11 - i)
	}

	rev = 11 - (add % 11)
	if rev > 9 {
		rev = 0
	}

	if rev != cpf[10] {
		return false
	}

	return true
}

func (cpf CPF) allDigitsAreEqual() bool {
	for i := 1; i < 11; i++ {
		if cpf[i] != cpf[0] {
			return false
		}
	}

	return true
}

func main() {
	runtime.GOMAXPROCS(2)

	jobs := make(chan CPF, 1024)
	results := make(chan bool, 1024)
	done := make(chan bool)
	numberOfWorkers := 8
	numberOfJobs := 99999999999

	for i := 0; i < numberOfWorkers; i++ {
		go func(cpfs chan CPF, result chan bool, done chan bool) {
			for {
				select {
				case cpf := <-cpfs:
					result <- cpf.Valid()
				case <-done:
					return
				}
			}
		}(jobs, results, done)
	}

	go func() {
		for i := 0; i < numberOfJobs; i++ {
			jobs <- NewCPF(int64(i))
		}
	}()

	go func() {
		count := 0
		valids := 0
		invalids := 0

		for {
			if <-results {
				valids++
			} else {
				invalids++
			}

			count++

			if count%1000000 == 0 {
				fmt.Printf("@ %d (valids: %d, invalids: %d)\n", count, valids, invalids)
			}

			if count >= numberOfJobs {
				fmt.Println("valids:", valids)
				fmt.Println("invalids:", invalids)

				done <- true
				return
			}
		}
	}()

	<-done
}