#include <algorithm>
#include <cassert>
#include <iostream>
#include <vector>

int main() {
    std::vector<int> values{5, 2, 3, 2, 4, 1};
    std::sort(values.begin(), values.end());
    assert((values == std::vector<int>{1, 2, 2, 3, 4, 5}));
    auto first = std::lower_bound(values.begin(), values.end(), 2);
    auto last = std::upper_bound(values.begin(), values.end(), 2);
    assert(last - first == 2);
    assert(std::lower_bound(values.begin(), values.end(), 9) == values.end());

    auto new_end = std::remove_if(values.begin(), values.end(),
                                  [](int x) { return x % 2 == 0; });
    assert(values.size() == 6 && new_end - values.begin() == 3);
    values.erase(new_end, values.end());
    assert((values == std::vector<int>{1, 3, 5}));
    std::cout << values[0] << ' ' << values[1] << ' ' << values[2] << '\n';
}