A-M baby

Task/Hailstone-sequence/JavaScript/hailstone-sequence.js

@@ -0,0 +1,23 @@
+function hailstone (n) {
+    var seq = [n];
+    while (n > 1) {
+        n = n % 2 ? 3 * n + 1 : n / 2;
+        seq.push(n);
+    }
+    return seq;
+}
+
+// task 2: verify the sequence for n = 27
+var h = hailstone(27), hLen = h.length;
+print("sequence 27 is (" + h.slice(0, 4).join(", ") + " ... "
+    + h.slice(hLen - 4, hLen).join(", ") + "). length: " + hLen);
+
+// task 3: find the longest sequence for n < 100000
+for (var n, max = 0, i = 100000; --i;) {
+    var seq = hailstone(i), sLen = seq.length;
+    if (sLen > max) {
+        n = i;
+        max = sLen;
+    }
+}
+print("longest sequence: " + max + " numbers for starting point " + n);