1 #include 
     
       2 #include 
      
        3 #include 
       
         4 using namespace std; 5 string LongToString(long l) 6 { 7     stringstream str; 8     str<
        
         >l;15     string str = LongToString(l);16     size_t len = str.length();17     for(int index =(int) len-3; index > 0; index -= 3)18       str.insert(index, ",");19     cout<
         
          <