tests/bench_421.nit

   1 # This file is part of NIT ( http://www.nitlanguage.org ).
   2 #
   3 # Copyright 2005-2008 Jean Privat <jean@pryen.org>
   4 #
   5 # Licensed under the Apache License, Version 2.0 (the "License");
   6 # you may not use this file except in compliance with the License.
   7 # You may obtain a copy of the License at
   8 #
   9 #     http://www.apache.org/licenses/LICENSE-2.0
  10 #
  11 # Unless required by applicable law or agreed to in writing, software
  12 # distributed under the License is distributed on an "AS IS" BASIS,
  13 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  14 # See the License for the specific language governing permissions and
  15 # limitations under the License.
  16
  17 meth count_421(n: Int): Int
  18 # Return the number of steps to come back to 1
  19 do
  20         var steps = 0
  21         while n > 1 do
  22                 steps = steps + 1
  23                 if n % 2 == 0 then
  24                         n = n / 2
  25                 else
  26                         n = n * 3 + 1
  27                 end
  28         end
  29         return steps
  30 end
  31
  32 var n = 10
  33 if not args.is_empty then
  34         n = args.first.to_i
  35 end
  36
  37 var max_i = 1
  38 var max_v = 0
  39 for i in [2..n] do
  40         var v = count_421(i)
  41         if v >= max_v then
  42                 max_i = i
  43                 max_v = v
  44         end
  45 end
  46
  47 print("{max_i}: {max_v}")