std::vector<int> v1;

std::vector<int> v2 {1, 2, 3};

std::vector<int> v3 (26);

v1.push_back(11);

std::cout << v1[0] << std::endl;

for (int i=0; i<v3.size(); i++){

std::cout << v3[i] << std::endl;

}

bool is_empty = v1.empty();

int end = v2.back();

v2.pop_back();

std::set<int> s1;

std::set<int> s2 { 1, 2, 3, 4, 5 };

std::vector<int> v {7, 8, 9};

std::set<int> s3 (v.begin(), v.end());

s1.insert(69);

s1.erase(69);

int val_is_in_set = s2.count(3);

int num_elements = s2.size();

std::unordered_map<int, int> map1;

std::unordered_map<int, int> map2 {{1, 11}, {2, 22}};

if (map2.count(2)){

std::cout << map2[2] << std::endl;

} else {

map2[2]=22;

}

int size = map2.size();

for (auto [key, val] : map2){

std::cout << key << ": " << val << std::endl;

}

for (auto x: map2){

int key = x.first;

int val = x.second;

}

// if we want to push and pop from both sides of the queue, need to use deque (double ended queue) instead.

std::queue<int> q1;

std::deque<int> q2;

q2.push_front(1);

q2.push_back(2);

int back = q2.back();

int front = q2.front();

q2.pop_back();

q2.pop_front();

q1.push(66); // push to back of queue

q1.push(77);

int front2 = q1.front();

int back2 = q1.back();

q1.pop(); // pops from left side of queue

// Max heap by default

std::priority_queue<int> heap1; // cant initialize

std::vector<int> arr {1, 2, 3};

std::priority_queue<int> heap2 (arr.begin(), arr.end());

heap1.push(11);

heap1.push(22);

heap1.push(33);

int top = heap1.top();

heap1.pop();

bool is_empty = heap1.empty();

int size = heap2.size();

vectors_test();

queue_test();

test_heap();

// set_test();

// map_test();

return 0;