Initial data commit

Task/Subtractive-generator/Java/subtractive-generator.java

@@ -0,0 +1,53 @@
+import java.util.function.IntSupplier;
+import static java.util.stream.IntStream.generate;
+
+public class SubtractiveGenerator implements IntSupplier {
+    static final int MOD = 1_000_000_000;
+    private int[] state = new int[55];
+    private int si, sj;
+
+    public SubtractiveGenerator(int p1) {
+        subrandSeed(p1);
+    }
+
+    void subrandSeed(int p1) {
+        int p2 = 1;
+
+        state[0] = p1 % MOD;
+        for (int i = 1, j = 21; i < 55; i++, j += 21) {
+            if (j >= 55)
+                j -= 55;
+            state[j] = p2;
+            if ((p2 = p1 - p2) < 0)
+                p2 += MOD;
+            p1 = state[j];
+        }
+
+        si = 0;
+        sj = 24;
+        for (int i = 0; i < 165; i++)
+            getAsInt();
+    }
+
+    @Override
+    public int getAsInt() {
+        if (si == sj)
+            subrandSeed(0);
+
+        if (si-- == 0)
+            si = 54;
+        if (sj-- == 0)
+            sj = 54;
+
+        int x = state[si] - state[sj];
+        if (x < 0)
+            x += MOD;
+
+        return state[si] = x;
+    }
+
+    public static void main(String[] args) {
+        generate(new SubtractiveGenerator(292_929)).limit(10)
+                .forEach(System.out::println);
+    }
+}