langs a-z

Task/Factorial/NetRexx/factorial.netrexx

@@ -0,0 +1,51 @@
+/* NetRexx */
+
+options replace format comments java crossref savelog symbols nobinary
+
+numeric digits 64 -- switch to exponential format when numbers become larger than 64 digits
+
+say 'Input a number: \-'
+say
+do
+  n_ = long ask -- Gets the number, must be an integer
+
+  say n_'! =' factorial(n_) '(using iteration)'
+  say n_'! =' factorial(n_, 'r') '(using recursion)'
+
+  catch ex = Exception
+    ex.printStackTrace
+end
+
+return
+
+method factorial(n_ = long, fmethod = 'I') public static returns Rexx signals IllegalArgumentException
+
+  if n_ < 0 then -
+    signal IllegalArgumentException('Sorry, but' n_ 'is not a positive integer')
+
+  select
+    when fmethod.upper = 'R' then -
+      fact = factorialRecursive(n_)
+    otherwise -
+      fact = factorialIterative(n_)
+    end
+
+  return fact
+
+method factorialIterative(n_ = long) private static returns Rexx
+
+  fact = 1
+  loop i_ = 1 to n_
+    fact = fact * i_
+    end i_
+
+  return fact
+
+method factorialRecursive(n_ = long) private static returns Rexx
+
+  if n_ > 1 then -
+    fact = n_ * factorialRecursive(n_ - 1)
+  else -
+   fact = 1
+
+  return fact