Data commit

Task/Hailstone-sequence/Aime/hailstone-sequence.aime

@@ -0,0 +1,58 @@
+void
+print_hailstone(integer h)
+{
+    list l;
+
+    while (h ^ 1) {
+        lb_p_integer(l, h);
+        h = h & 1 ? 3 * h + 1 : h / 2;
+    }
+
+    o_form("hailstone sequence for ~ is ~1 ~ ~ ~ .. ~ ~ ~ ~, it is ~ long\n",
+           l[0], l[1], l[2], l[3], l[-3], l[-2], l[-1], 1, ~l + 1);
+}
+
+void
+max_hailstone(integer x)
+{
+    integer e, i, m;
+    index r;
+
+    m = 0;
+    i = 1;
+    while (i < x) {
+        integer h, k, l;
+
+        h = i;
+        l = 1;
+        while (h ^ 1) {
+            if (i_j_integer(k, r, h)) {
+                l += k;
+                break;
+            } else {
+                l += 1;
+                h = h & 1 ? 3 * h + 1 : h / 2;
+            }
+        }
+
+        r[i] = l - 1;
+
+        if (m < l) {
+            m = l;
+            e = i;
+        }
+
+        i += 1;
+    }
+
+    o_form("hailstone sequence length for ~ is ~\n", e, m);
+}
+
+integer
+main(void)
+{
+    print_hailstone(27);
+    max_hailstone(100000);
+
+    return 0;
+}