June 2018 Update

Task/Unbias-a-random-generator/Java/unbias-a-random-generator-2.java

@@ -0,0 +1,28 @@
+// version 1.1.2
+
+fun biased(n: Int) = Math.random() < 1.0 / n
+
+fun unbiased(n: Int): Boolean {
+    var a: Boolean
+    var b: Boolean
+    do {
+        a = biased(n)
+        b = biased(n)
+    }
+    while (a == b)
+    return a
+}
+
+fun main(args: Array<String>) {
+    val m = 50_000
+    val f = "%d: %2.2f%%  %2.2f%%"
+    for (n in 3..6) {
+        var c1 = 0
+        var c2 = 0
+        for (i in 0 until m) {
+            if (biased(n)) c1++
+            if (unbiased(n)) c2++
+        }
+        println(f.format(n, 100.0 * c1 / m, 100.0 * c2 / m))
+    }
+}