#include <algorithm>
#include <iostream>
#include <iomanip>
#include <string>

int main()
{
  std::string s = "ein Beispiel";
  std::cout << s << '\n';

  auto q = std::partition(begin(s), end(s), [](char c) { return c < 'i'; ));

  std::cout << s << '\n'
            << std::setw(q-begin(s)+1) << "^" << " davor kleiner als i\n";
}