2016 Update

Task/Verify-distribution-uniformity-Naive/Java/verify-distribution-uniformity-naive.java

@@ -0,0 +1,29 @@
+import static java.lang.Math.abs;
+import java.util.*;
+import java.util.function.IntSupplier;
+
+public class Test {
+
+    static void distCheck(IntSupplier f, int nRepeats, double delta) {
+        Map<Integer, Integer> counts = new HashMap<>();
+
+        for (int i = 0; i < nRepeats; i++)
+            counts.compute(f.getAsInt(), (k, v) -> v == null ? 1 : v + 1);
+
+        double target = nRepeats / (double) counts.size();
+        int deltaCount = (int) (delta / 100.0 * target);
+
+        counts.forEach((k, v) -> {
+            if (abs(target - v) >= deltaCount)
+                System.out.printf("distribution potentially skewed "
+                        + "for '%s': '%d'%n", k, v);
+        });
+
+        counts.keySet().stream().sorted().forEach(k
+                -> System.out.printf("%d %d%n", k, counts.get(k)));
+    }
+
+    public static void main(String[] a) {
+        distCheck(() -> (int) (Math.random() * 5) + 1, 1_000_000, 1);
+    }
+}