#include <iostream>
#include <vector>
#include <cassert>
using namespace std;

vector <int> vector_set;

void destroy_vector_set() {
    vector_set.clear();
}

bool check_element_exist(int number) {
    for (auto element : vector_set) {
        if (element == number) {
            return false;
        }
    }
    return true;
}

void add_element(int number) {
    if (check_element_exist(number)) {
        vector_set.push_back(number);
    }
}

bool delete_element(int number) {
    for (int i = 0; i < vector_set.size(); i++) {
        if (vector_set[i] == number) {
            vector_set.erase(vector_set.begin() + i);
            return true;
        }
    }
    return false;
}

int find_element(int number) {
    for (auto element : vector_set) {
        if (element == number) {
            return true;
        }
    }
    return false;
}

int get_element(int number) {
    for (auto element : vector_set) {
        if (element == number) {
            return element;
        }
    }
    throw std::runtime_error("number isn't exist");
}

//Тесты
void can_add_elements_to_vector_set_test() {
    destroy_vector_set();

    for (int i = 0; i < 2000; i++) {
        add_element(i);
    }
    for (int i = 0; i < 2000; i++) {
        int current_element = get_element(i);
        assert(current_element == i);
    }
}

void cannot_delete_not_existed_element_test() {
    destroy_vector_set();

    for (int i = 0; i < 1000; i++) {
        add_element(i);
    }

    assert(delete_element(1000) == false);
    assert(delete_element(2000) == false);
    assert(delete_element(2500) == false);
    assert(delete_element(3000) == false);
}

void can_delete_existed_element_test() {
    destroy_vector_set();

    for (int i = 0; i < 5; i++) {
        add_element(i * 2);
    }

    assert(delete_element(2) == true);
    assert(delete_element(6) == true);

    assert(get_element(0) == 0);
    assert(get_element(4) == 4);
    assert(get_element(8) == 8);
}

void can_find_element_with_valid_value_test() {
    destroy_vector_set();

    for (int i = 0; i < 10; i++) {
        add_element(i + 2);
    }

    for (int i = 0; i < 10; i++) {
        assert(find_element(i + 2) == true);
    }
}

void cannot_find_element_with_invalid_value_test() {
    destroy_vector_set();

    for (int i = 0; i < 10; ++i) {
        add_element(i + 2);
    }

    assert(find_element(0) == false);

    for (int i = 20; i < 100; i++) {
        assert(find_element(i) == false);
    }
}

int main() {
    can_add_elements_to_vector_set_test();
    cannot_delete_not_existed_element_test;
    can_delete_existed_element_test();
    can_find_element_with_valid_value_test();
    cannot_find_element_with_invalid_value_test();

    system("PAUSE");
    return 0;
}