How not to land a job.

gistfile1.cpp

// Whatever you do, when asked to enumerate permutations of length n,
// don't demonstrate that you can quickly produce this solution...

#include <algorithm>
#include <cerrno>
#include <cstdlib>
#include <iostream>
#include <iterator>
#include <numeric>
#include <stdexcept>
#include <vector>

int main(int argc, char *argv[])
{
    using namespace std;

    // Parse incoming single command line argument
    if (argc != 2) throw invalid_argument("argc != 2");
    errno = 0;
    char *end;
    const unsigned long n = strtoul(argv[1], &end, 10);
    if (errno || end == argv[1]) throw invalid_argument(argv[1]);

    // Output the requested permutations
    vector<unsigned long> s(n, 1);
    partial_sum(s.begin(), s.end(), s.begin());
    do {
        copy(s.begin(), s.end(), ostream_iterator<unsigned long>(cout, " "));
        cout << '\n';
    } while (next_permutation(s.begin(), s.end()));

    return EXIT_SUCCESS;
}

// ...but instead mumble briefly about how next_permutation works,
// worry about the algorithmic internals of std::next_permutation for 10
// minutes in front of a blank whiteboard.  Ultimately produce nothing.  And
// then ask the interviewer to please move on.