Counts the number of unique characters in a string. - C++ STL

C++ examples for STL:string

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Description

Counts the number of unique characters in a string.

Demo Code

#include <string>
#include <iostream>

template<typename T>
int countUnique(const std::basic_string<T>& s) {
   using std::basic_string;

   basic_string<T> chars;//from  www .  ja v a2s . com

   for (typename basic_string<T>::const_iterator p = s.begin();
        p != s.end(); ++p) {
     if (chars.find(*p) == basic_string<T>::npos)
        chars += *p;
   }
   return(chars.length());
}

int main() {
   std::string s = "this is a test";
   std::cout << countUnique(s) << '\n';
}

Result


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