теория1.1

#include <iostream>
#include <vector>
#include <algorithm>
#include <set>
using namespace std;
int main() {
    set<int> my_set;
    my_set = {1,2,3};
    for(int i = 0 ; i < my_set.size() ; i++){
        cout << my_set.count(i+1) << " ";
    }
    cout << endl;
    for(int i = 0 ; i < my_set.size() ; i++){
        auto it = my_set.find(i+1);
        cout << *it << " ";
    }
    auto it_begin = my_set.begin();
    cout<<*it_begin;//my_set.end();

    cout << endl;

    my_set.insert(1);
    cout << endl;
    //el = 10
    //if (my_set.count(el) == 1){}
    // if (my_set.find(el) != my_set.end()){}
    my_set = {1,2,3,4};
    my_set.erase(2); // erase(my_set.find(2))

    multiset<int> my_kek;
    my_kek = {1,1,2,2,3,3,4,5};

    my_kek.erase(2); // {1,2,3,3,4,5}
    return 0;
}