Data commit

Task/Lah-numbers/Dyalect/lah-numbers.dyalect

@@ -0,0 +1,19 @@
+func fact(n) =>
+    n is 0 ? 1 : (n^-1..<0).Fold(1, (acc, val) => acc * val)
+
+func lah(n, k) {
+    return fact(n) when k is 1
+    return 1 when k == n
+    return 0 when k > n || k < 1 || n < 1
+    (fact(n) * fact(n - 1)) / (fact(k) * fact(k - 1)) / fact(n - k)
+}
+
+print("Unsigned Lah numbers: L(n, k):");
+print("n/k ", terminator: "");
+(0..12).ForEach(i => i >> "{0,10} ".Format >> print(terminator: ""))
+print("")
+(0..12).ForEach(row => {
+    row >> "{0,-3}".Format >> print(terminator: "")
+    (0..row).ForEach(i => lah(row, i) >> "{0,11}".Format >> print(terminator: ""))
+    print("")
+})