import scala.util.Random
object DistinctDigitGenerator {
// ------------------------------------------------------------
// Function: generate_number
// Purpose: Create one 3-digit integer with distinct digits,
// drawn from a shared pool of available digits.
// The first digit is never zero, so the result
// is always a true 3-digit integer.
// ------------------------------------------------------------
def generate_number(available_digits: scala.collection.mutable.ListBuffer[String],
length: Int = 3): Int = {
// Choose the first digit from the pool, excluding '0'
val non_zero_digits = available_digits.filter(_ != "0")
val first_digit = non_zero_digits(Random.nextInt(non_zero_digits.size))
available_digits -= first_digit
// Choose the remaining digits from the updated pool
val remaining = scala.collection.mutable.ListBuffer[String]()
for (_ <- 1 until length) {
val d = available_digits(Random.nextInt(available_digits.size))
remaining += d
available_digits -= d
}
// Build the number as a string, then convert to int
val digits_str = first_digit + remaining.mkString("")
digits_str.toInt
}
// ------------------------------------------------------------
// Function: generate_three_distinct_digit_numbers
// Purpose: Produce three integers, each with distinct digits,
// and no digit repeated across all three numbers.
// All numbers are guaranteed to be 3 digits long.
// ------------------------------------------------------------
def generate_three_distinct_digit_numbers(): (Int, Int, Int) = {
// Start with all digits 0–9 as strings
val digits = scala.collection.mutable.ListBuffer[String]()
for (i <- 0 to 9) digits += i.toString
// Generate three numbers, each 3 digits long
val n1 = generate_number(digits)
val n2 = generate_number(digits)
val n3 = generate_number(digits)
(n1, n2, n3)
}
// ------------------------------------------------------------
// Main execution
// ------------------------------------------------------------
def main(args: Array[String]): Unit = {
// Run the generator 5 times
for (_ <- 1 to 5) {
val (n1, n2, n3) = generate_three_distinct_digit_numbers()
println(s"($n1, $n2, $n3)")
}
}
}
/*
run:
(172, 608, 935)
(193, 256, 407)
(250, 897, 413)
(693, 420, 751)
(954, 608, 231)
*/
