字符流中第一个不重复的字符

 1 class Solution
 2 {
 3 public:
 4   //Insert one char from stringstream
 5     Solution():index_(0)
 6         {
 7         for(int i=0;i<256;i++)
 8             {
 9             ascii[i]=-1;
10         }
11     }
12     void Insert(char ch)
13     {
14          if(ascii[ch]==-1)
15              ascii[ch]=index_;
16          else if(ascii[ch]>=0)
17             ascii[ch]=-2;
18              index_++;
19     }
20   //return the first appearence once char in current stringstream
21     char FirstAppearingOnce()
22     {
23       int minIndex=65535;
24       char ch=‘#‘;
25         for(int i=0;i<256;i++)
26             {
27             if(ascii[i]>=0&&minIndex>ascii[i])
28                 {
29                 ch=(char)i;
30                 minIndex=ascii[i];
31             }
32         }   
33         return ch;
34       
35     }
36 private:
37     int ascii[256];
38     int index_;
39 };