Data commit

Task/Digital-root/Crystal/digital-root-1.crystal

@@ -0,0 +1,13 @@
+def digital_root(n : Int, base = 10) : Int
+  max_single_digit = base - 1
+  n = n.abs
+  if n > max_single_digit
+    n = 1 + (n - 1) % max_single_digit
+  end
+  n
+end
+
+puts digital_root 627615
+puts digital_root 39390
+puts digital_root 588225
+puts digital_root 7, base: 3

Task/Digital-root/Crystal/digital-root-2.crystal

@@ -0,0 +1,18 @@
+def digital_root_with_persistence(n : Int) : {Int32, Int32}
+  n = n.abs
+  persistence = 0
+
+  until n <= 9
+    persistence += 1
+
+    digit_sum = (0..(Math.log10(n).floor.to_i)).sum { |i| (n % 10**(i + 1) - n % 10**i) // 10**i }
+
+    n = digit_sum
+  end
+
+  {n, persistence}
+end
+
+puts digital_root_with_persistence 627615
+puts digital_root_with_persistence 39390
+puts digital_root_with_persistence 588225

Task/Digital-root/Crystal/digital-root-3.crystal

@@ -0,0 +1,18 @@
+def digital_root_with_persistence_to_s(n : Int) : {Int32, Int32}
+  n = n.abs
+  persistence = 0
+
+  until n <= 9
+    persistence += 1
+
+    digit_sum = n.to_s.chars.sum &.to_i
+
+    n = digit_sum
+  end
+
+  {n, persistence}
+end
+
+puts digital_root_with_persistence_to_s 627615
+puts digital_root_with_persistence_to_s 39390
+puts digital_root_with_persistence_to_s 588225