Data commit

Task/Fusc-sequence/Groovy/fusc-sequence.groovy

@@ -0,0 +1,39 @@
+class FuscSequence {
+    static void main(String[] args) {
+        println("Show the first 61 fusc numbers (starting at zero) in a horizontal format")
+        for (int n = 0; n < 61; n++) {
+            printf("%,d ", fusc[n])
+        }
+
+        println()
+        println()
+        println("Show the fusc number (and its index) whose length is greater than any previous fusc number length.")
+        int start = 0
+        for (int i = 0; i <= 5; i++) {
+            int val = i != 0 ? (int) Math.pow(10, i) : -1
+            for (int j = start; j < FUSC_MAX; j++) {
+                if (fusc[j] > val) {
+                    printf("fusc[%,d] = %,d%n", j, fusc[j])
+                    start = j
+                    break
+                }
+            }
+        }
+    }
+
+    private static final int FUSC_MAX = 30000000
+    private static int[] fusc = new int[FUSC_MAX]
+
+    static {
+        fusc[0] = 0
+        fusc[1] = 1
+        for (int n = 2; n < FUSC_MAX; n++) {
+            int n2 = (int) (n / 2)
+            int n2m = (int) ((n - 1) / 2)
+            int n2p = (int) ((n + 1) / 2)
+            fusc[n] = n % 2 == 0
+                ? fusc[n2]
+                : fusc[n2m] + fusc[n2p]
+        }
+    }
+}