Miscellany

#include <iostream>#include <fstream>#include <string>#include <vector>#include <iterator>#include <algorithm>int main(int argc, char* argv[]){    if (argc < 3) { std::cout << "Need at least 2 files." << std::endl; return -1; }    std::vector<std::string> one;    std::vector<std::string> two;    std::ifstream a(argv[1]);    std::ifstream b(argv[2]);    std::copy(std::istream_iterator<std::string>(a),         std::istream_iterator<std::string>(),         std::back_inserter(one));    std::copy(std::istream_iterator<std::string>(b),         std::istream_iterator<std::string>(),         std::back_inserter(two));    for(auto i : two) {        auto s = std::find(one.begin(), one.end(), i);        if (s != one.end()) { one.erase(s); }    }    std::copy(one.begin(), one.end(),           std::ostream_iterator<std::string>(std::cout, "\n"));}