RosettaCodeData/Task/Tau-function/Scala/tau-function.scala

42 lines
803 B
Scala

object TauFunction {
private def divisorCount(n: Long): Long = {
var count = 1L
var number = n
// Deal with powers of 2 first
while ((number & 1L) == 0) {
count += 1
number >>= 1
}
// Odd prime factors up to the square root
var p = 3L
while (p * p <= number) {
var tempCount = 1L
while (number % p == 0) {
tempCount += 1
number /= p
}
count *= tempCount
p += 2
}
// If n > 1 then it's prime
if (number > 1) {
count *= 2
}
count
}
def main(args: Array[String]): Unit = {
val limit = 100
println(s"Count of divisors for the first $limit positive integers:")
for (n <- 1 to limit) {
print(f"${divisorCount(n)}%3d")
if (n % 20 == 0) println()
}
}
}