STL - General Questions

What will be the output of the program?

#include <iostream>
using namespace std;
#include <vector>
#include <numeric>
int main() {
    vector<int> v = {1, 2, 3, 4};
    cout << accumulate(v.begin(), v.end(), 10) << endl;
    return 0;
}

What will be the output of the program?

#include <iostream>
using namespace std;
#include <queue>
int main() {
    priority_queue<int> pq;
    pq.push(4); pq.push(9); pq.push(1);
    cout << pq.top() << endl;
    return 0;
}

What will be the output of the program?

#include <iostream>
using namespace std;
#include <deque>
int main() {
    deque<int> d;
    d.push_back(2); d.push_front(1); d.push_back(3);
    cout << d.front() << d.back() << d.size() << endl;
    return 0;
}

What will be the output of the program?

#include <iostream>
using namespace std;
#include <vector>
int main() {
    vector<int> v = {3, 1, 4};
    v.push_back(1);
    cout << v.size() << " " << v[2] << endl;
    return 0;
}

What will be the output of the program?

#include <iostream>
#include <string>
using namespace std;
#include <map>
int main() {
    map<string, int> m;
    m["b"] = 2; m["a"] = 1; m["b"] += 5;
    for (auto &p : m) cout << p.first << p.second << " ";
    cout << endl;
    return 0;
}