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1. A C++ std::set named s holds {10, 20, 30}. What does s.upper_bound(20) return?

the position of 20the position of 30the end positionthe position of 10

2. Why does this call fail to compile? ``

cpp
#include <algorithm>
#include <map>

int main() {
    std::map<int, int> m = {{10, 1}, {20, 2}, {30, 3}};
    auto it = std::lower_bound(m.begin(), m.end(), 15);
}

``

Map iterators cannot be incrementedlower_bound only works on vectorsThe map was not sortedMap elements are pairs, so comparing one with a plain int has no operator<

3. What does this program print? ``

cpp
#include <iostream>
#include <iterator>
#include <set>

int main() {
    std::set<int> s = {10, 20, 30, 40};
    auto it = s.lower_bound(25);
    std::cout << *it << ' ' << *std::prev(s.upper_bound(25)) << '\n';
}

``

30 2020 3025 2030 30

4. What does this program print? ``

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

int main() {
    std::vector<int> v = {2, 4, 4, 4, 9};
    auto lo = std::lower_bound(v.begin(), v.end(), 3);
    auto hi = std::upper_bound(v.begin(), v.end(), 9);
    std::cout << std::distance(lo, hi) << ' ' << (hi == v.end()) << '\n';
}

``

3 04 14 05 1

5. Name the member function of std::set that returns an iterator to the first element that is greater than or equal to a value. Type the name only, without parentheses.

Type your answer.

Ordered lookups