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stackoverflow-39080475-compilation-error-in-array-of-strings.cpp

#include<iostream>
#include<vector>
#include<string>
#include<set>

auto numberOfUniqueChars(std::string const& str) {
  std::set<char> s;
  for(auto c : str) {
    s.insert(c);
  }
  
  return s.size();
}

auto getStringWithTheMostUniqueChars(std::vector<std::string> const& strings) {
  size_t maxCount = 0;
  std::string result;
  for(auto s : strings) {
    const auto currentCount = numberOfUniqueChars(s);
    if( currentCount > maxCount ) {
      result = s;
      maxCount = currentCount;
    }
  }
  return result;
}

auto test0(){
  return getStringWithTheMostUniqueChars(
    {}   
  ) == "";
}

auto test1(){
  return getStringWithTheMostUniqueChars(
    {"asd", "asdf", "aaa" }   
  ) == "asdf";
}


int main() {
  std::vector<std::string> strings;

  std::cout << "enter your strings; enter $ to end" <<std::endl;
  while (1) {
    std::string line;
    std::getline(std::cin, line);
    if(line=="$") break;
    std::cout << "input: " 
      << '\"' << line <<'\"' 
      << " unique chars: " 
      << numberOfUniqueChars(line) 
      << std::endl;
    strings.push_back(line);
  }
  
  std::cout << "string with most unique chars: "
    << getStringWithTheMostUniqueChars(strings)
    << std::endl;
  return 0;
}

/*
  press play and call main or testX
*/