Data commit

Task/Knuths-power-tree/Sidef/knuths-power-tree.sidef

@@ -0,0 +1,38 @@
+var lvl = [[1]]
+var p = Hash(1 => 0)
+
+func path(n) is cached {
+    n || return []
+    while (n !~ p) {
+        var q = []
+        for x in lvl[0] {
+            for y in path(x) {
+                break if (x+y ~~ p)
+                y = x+y
+                p{y} = x
+                q << y
+            }
+        }
+        lvl[0] = q
+    }
+    path(p{n}) + [n]
+}
+
+func tree_pow(x, n) {
+    var r = Hash(0 => 1, 1 => x)
+    var p = 0
+    for i in path(n) {
+        r{i} = (r{i-p} * r{p})
+        p = i
+    }
+    r{n}
+}
+
+func show_pow(x, n) {
+    var fmt = ("%d: %s\n" + ["%g^%s = %f", "%s^%s = %s"][x.is_int] + "\n")
+    print(fmt % (n, path(n), x, n, tree_pow(x, n)))
+}
+
+for x in ^18 { show_pow(2, x) }
+show_pow(1.1, 81)
+show_pow(3, 191)