Initial data commit

Task/Pseudo-random-numbers-Xorshift-star/Java/pseudo-random-numbers-xorshift-star.java

@@ -0,0 +1,47 @@
+public class XorShiftStar {
+    private static final long MAGIC = Long.parseUnsignedLong("2545F4914F6CDD1D", 16);
+    private long state;
+
+    public void seed(long num) {
+        state = num;
+    }
+
+    public int nextInt() {
+        long x;
+        int answer;
+
+        x = state;
+        x = x ^ (x >>> 12);
+        x = x ^ (x << 25);
+        x = x ^ (x >>> 27);
+        state = x;
+        answer = (int) ((x * MAGIC) >> 32);
+
+        return answer;
+    }
+
+    public float nextFloat() {
+        return (float) Integer.toUnsignedLong(nextInt()) / (1L << 32);
+    }
+
+    public static void main(String[] args) {
+        var rng = new XorShiftStar();
+        rng.seed(1234567);
+        System.out.println(Integer.toUnsignedString(rng.nextInt()));
+        System.out.println(Integer.toUnsignedString(rng.nextInt()));
+        System.out.println(Integer.toUnsignedString(rng.nextInt()));
+        System.out.println(Integer.toUnsignedString(rng.nextInt()));
+        System.out.println(Integer.toUnsignedString(rng.nextInt()));
+        System.out.println();
+
+        int[] counts = {0, 0, 0, 0, 0};
+        rng.seed(987654321);
+        for (int i = 0; i < 100_000; i++) {
+            int j = (int) Math.floor(rng.nextFloat() * 5.0);
+            counts[j]++;
+        }
+        for (int i = 0; i < counts.length; i++) {
+            System.out.printf("%d: %d\n", i, counts[i]);
+        }
+    }
+}