Finding common characters in two strings

Question

I am coding for the problem in which we got to count the number of common characters in two strings. Main part of the count goes like this

for(i=0; i < st         


        

Answer 1

for (std::vector::iterator i = s1.begin(); i != s1.end(); ++i)
{
    if (std::find(s2.begin(), s2.end(), *i) != s2.end())
   {
    dest.push_back(*i);
   }
}

taken from here