Initial data commit

Task/Digital-root-Multiplicative-digital-root/Julia/digital-root-multiplicative-digital-root-1.julia

@@ -0,0 +1,10 @@
+function digitalmultroot{S<:Integer,T<:Integer}(n::S, bs::T=10)
+    -1 < n && 1 < bs || throw(DomainError())
+    ds = n
+    pers = 0
+    while bs <= ds
+        ds = prod(digits(ds, bs))
+        pers += 1
+    end
+    return (pers, ds)
+end

Task/Digital-root-Multiplicative-digital-root/Julia/digital-root-multiplicative-digital-root-2.julia

@@ -0,0 +1,34 @@
+const bs = 10
+const excnt = 5
+
+println("Testing Multiplicative Digital Root.\n")
+for i in [123321, 7739, 893, 899998]
+    (pers, ds) = digitalmultroot(i, bs)
+    print(@sprintf("%8d", i))
+    print(" has persistence ", pers)
+    println(" and digital root ", ds)
+end
+
+dmr = zeros(Int, bs, excnt)
+hasroom = trues(bs)
+dex = ones(Int, bs)
+
+i = 0
+while any(hasroom)
+    (pers, ds) = digitalmultroot(i, bs)
+    ds += 1
+    if hasroom[ds]
+        dmr[ds, dex[ds]] = i
+        dex[ds] += 1
+        if dex[ds] > excnt
+            hasroom[ds] = false
+        end
+    end
+    i += 1
+end
+
+println("\n MDR:    First ", excnt, " numbers having this MDR")
+for (i, d) in enumerate(0:(bs-1))
+    print(@sprintf("%4d: ", d))
+    println(join([@sprintf("%6d", dmr[i, j]) for j in 1:excnt], ","))
+end