examples/ugly.cs

   1 #region license
   2 // Copyright (c) 2004, Rodrigo B. de Oliveira (rbo@acm.org)
   3 // All rights reserved.
   4 //
   5 // Redistribution and use in source and binary forms, with or without modification,
   6 // are permitted provided that the following conditions are met:
   7 //
   8 //     * Redistributions of source code must retain the above copyright notice,
   9 //     this list of conditions and the following disclaimer.
  10 //     * Redistributions in binary form must reproduce the above copyright notice,
  11 //     this list of conditions and the following disclaimer in the documentation
  12 //     and/or other materials provided with the distribution.
  13 //     * Neither the name of Rodrigo B. de Oliveira nor the names of its
  14 //     contributors may be used to endorse or promote products derived from this
  15 //     software without specific prior written permission.
  16 //
  17 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
  18 // ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  19 // WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  20 // DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
  21 // FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22 // DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  23 // SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  24 // CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  25 // OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  26 // THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27 #endregion
  28
  29
  30 using System;
  31 using System.Collections;
  32
  33 public class App
  34 {
  35         public static long value(long x, long y, long z)
  36         {
  37                 return (long)(Math.Pow(2, x)*Math.Pow(3, y)*Math.Pow(5, z));
  38         }
  39
  40         public static long ugly(int max)
  41         {
  42                 ArrayList uglies = new ArrayList();
  43                 long counter = 1;
  44                 Hashtable dict = new Hashtable();
  45                 dict[counter] = new long[] { 0, 0, 0 };
  46
  47                 while (uglies.Count < max)
  48                 {
  49                         uglies.Add(counter);
  50                         long[] array = (long[])dict[counter];
  51                         long x = array[0];
  52                         long y = array[1];
  53                         long z = array[2];
  54
  55                         dict[value(x+1, y, z)] = new long[] { x+1, y, z };
  56                         dict[value(x, y+1, z)] = new long[] { x, y+1, z };
  57                         dict[value(x, y, z+1)] = new long[] { x, y, z+1 };
  58
  59                         dict.Remove(counter);
  60
  61                         ArrayList keys = new ArrayList(dict.Keys);
  62                         keys.Sort();
  63
  64                         counter = (long)keys[0];
  65                 }
  66
  67                 return (long)uglies[uglies.Count-1];
  68         }
  69
  70         public static void Main()
  71         {
  72                 int iter = 1500;
  73                 DateTime start = DateTime.Now;
  74                 long uvalue = 0;
  75                 for (int i=0; i<10; ++i)
  76                 {
  77                         uvalue = ugly(iter);
  78                 }
  79                 DateTime end = DateTime.Now;
  80                 Console.WriteLine("{0} ugly value = {1} in {2}ms", iter, uvalue, (end-start).TotalMilliseconds);
  81         }
  82 }
  83