Initial data commit

Task/Superpermutation-minimisation/Java/superpermutation-minimisation.java

@@ -0,0 +1,51 @@
+import static java.util.stream.IntStream.rangeClosed;
+
+public class Test {
+    final static int nMax = 12;
+
+    static char[] superperm;
+    static int pos;
+    static int[] count = new int[nMax];
+
+    static int factSum(int n) {
+        return rangeClosed(1, n)
+                .map(m -> rangeClosed(1, m).reduce(1, (a, b) -> a * b)).sum();
+    }
+
+    static boolean r(int n) {
+        if (n == 0)
+            return false;
+
+        char c = superperm[pos - n];
+        if (--count[n] == 0) {
+            count[n] = n;
+            if (!r(n - 1))
+                return false;
+        }
+        superperm[pos++] = c;
+        return true;
+    }
+
+    static void superPerm(int n) {
+        String chars = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
+
+        pos = n;
+        superperm = new char[factSum(n)];
+
+        for (int i = 0; i < n + 1; i++)
+            count[i] = i;
+        for (int i = 1; i < n + 1; i++)
+            superperm[i - 1] = chars.charAt(i);
+
+        while (r(n)) {
+        }
+    }
+
+    public static void main(String[] args) {
+        for (int n = 0; n < nMax; n++) {
+            superPerm(n);
+            System.out.printf("superPerm(%2d) len = %d", n, superperm.length);
+            System.out.println();
+        }
+    }
+}