text: #include <iostream>
  #include <vector>
  
  using namespace std;
  
  void reverseString(vector<char> &s) {
  
    vector<char>::iterator ix = s.end() - 1;
  
    for (vector<char>::iterator it = s.begin(); it < (s.begin() + s.size() / 2);
         it++) {
      char temp = *it;
      *it = *ix;
      *ix = temp;
      ix--;
    }
  }
  
  int main(int argc, char const *argv[]) {
    vector<char> s{'h', 'e', 'l', 'l', 'o'};
  
    reverseString(s);
  
    for (vector<char>::iterator it = s.begin(); it != s.end(); ++it) {
      cout << *it << endl;
    }
  
    return 0;
  }