Data update

Task/Bulls-and-cows/Kotlin/bulls-and-cows.kotlin

@@ -1,26 +1,17 @@
-// version 1.1.2
-
-import java.util.Random
-
 const val MAX_GUESSES = 20  // say
 
-fun main(args: Array<String>) {
-    val r = Random()
-    var num: String
-    // generate a 4 digit random number from 1234 to 9876 with no zeros or repeated digits
-    do {
-        num = (1234 + r.nextInt(8643)).toString()
-    } while ('0' in num || num.toSet().size < 4)
+fun main() {
+    val num = ('1'..'9').shuffled().take(4).joinToString("")
 
     println("All guesses should have exactly 4 distinct digits excluding zero.")
     println("Keep guessing until you guess the chosen number (maximum $MAX_GUESSES valid guesses).\n")
     var guesses = 0
     while (true) {
         print("Enter your guess : ")
-        val guess = readLine()!!
+        val guess = readln().trim()
         if (guess == num) {
             println("You've won with ${++guesses} valid guesses!")
-            return
+            break
         }
         val n = guess.toIntOrNull()
         if (n == null)