Standard Copy

#include <iostream>
#include <iterator>
#include <algorithm>
#include <vector>

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

    std::copy(
        std::istream_iterator<std::string>(std::cin),
        std::istream_iterator<std::string>(),
        std::back_inserter(v)
    );

    std::copy(
        v.begin(),
        v.end(),
        std::ostream_iterator<std::string>(std::cout, " ")
    );

    return 0;
}