Initial data commit

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

@@ -0,0 +1,27 @@
+public class Bias {
+    public static boolean biased(int n) {
+        return Math.random() < 1.0 / n;
+    }
+
+    public static boolean unbiased(int n) {
+        boolean a, b;
+        do {
+            a = biased(n);
+            b = biased(n);
+        } while (a == b);
+        return a;
+    }
+
+    public static void main(String[] args) {
+        final int M = 50000;
+        for (int n = 3; n < 7; n++) {
+            int c1 = 0, c2 = 0;
+            for (int i = 0; i < M; i++) {
+                c1 += biased(n) ? 1 : 0;
+                c2 += unbiased(n) ? 1 : 0;
+            }
+            System.out.format("%d: %2.2f%%  %2.2f%%\n",
+                              n, 100.0*c1/M, 100.0*c2/M);
+        }
+    }
+}