1         static void Main(string[] args)
 2         {
 3             List<char> chars = new List<char>();
 4             chars.Add(' ');
 5             chars.Add('.');
 6             chars.Add('!');
 7             chars.Add(',');
 8             string str = "I love    Shanghai, and I love Beijing!";
 9             Console.WriteLine(Reverse(str, chars));
10         }
11 
12         private static string Reverse(string str, List<char> chars)
13         {
14             string result = "";
15             string word = "";            
16             char[] strArray = str.ToCharArray();
17             for (int i = strArray.Length - 1; i >= -1; i--)
18             {
19                 if (i == -1)
20                 {
21                     result += word;
22                     break;
23                 }
24 
25                 if (chars.Contains(strArray[i]))
26                 {
27                     if (word != "")
28                     {
29                         result += word;
30                         word = "";
31                     }
32                     
33                     result += strArray[i];                    
34                 }
35                 else
36                 {
37                     word = strArray[i] + word;                    
38                 }
39             }
40 
41             return result;
42         }