Initial data commit

Task/Tau-function/Java/tau-function.java

@@ -0,0 +1,33 @@
+public class TauFunction {
+    private static long divisorCount(long n) {
+        long total = 1;
+        // Deal with powers of 2 first
+        for (; (n & 1) == 0; n >>= 1) {
+            ++total;
+        }
+        // Odd prime factors up to the square root
+        for (long p = 3; p * p <= n; p += 2) {
+            long count = 1;
+            for (; n % p == 0; n /= p) {
+                ++count;
+            }
+            total *= count;
+        }
+        // If n > 1 then it's prime
+        if (n > 1) {
+            total *= 2;
+        }
+        return total;
+    }
+
+    public static void main(String[] args) {
+        final int limit = 100;
+        System.out.printf("Count of divisors for the first %d positive integers:\n", limit);
+        for (long n = 1; n <= limit; ++n) {
+            System.out.printf("%3d", divisorCount(n));
+            if (n % 20 == 0) {
+                System.out.println();
+            }
+        }
+    }
+}