tema

#include <iostream>
#include <string>
#include <vector>

template <typename T>
struct node
{
    T val;
    node* next;
};


int main()
{
    node<int32_t>* first = nullptr, *last = nullptr;

    uint16_t n;
    std::cin >> n;
    for (uint16_t i = 0; i < n; i++)
    {
        int32_t val;
        std::cin >> val;
        node<int32_t>* nNode = new node<int32_t>{ val, nullptr };

        if (first == nullptr)
        {
            first = last = nNode;
        }
        else
        {
            last->next = nNode;
            last = last->next;
        }
    }

    std::vector<std::pair<uint16_t, uint8_t>> frecv(10000, std::make_pair(0, 0));

    uint16_t secvMax = 0, secvCurr = 0;
    node<int32_t>* p = first;
    while (p != nullptr && p != last)
    {
        uint16_t delUntil = 0;
        for (uint16_t i = 0; i < n; i++)
        {
            if (frecv[p->val].second == 1)
            {
                delUntil = frecv[p->val].first;
                for (uint16_t j = 0; j < delUntil + 1; j++)
                {
                    first = first->next;
                    n--;
                }
                p = first;
                break;
            }
            frecv[p->val] = std::make_pair(i, 1);
            p = p->next;
            secvCurr++;
        }

        if (secvCurr > secvMax)
        {
            secvMax = secvCurr;
        }
        secvCurr = 0;
        frecv = std::vector<std::pair<uint16_t, uint8_t>>(10000, std::make_pair(0, 0));
    }

    std::cout << secvMax << std::endl;
    std::getchar(); std::getchar();

    return 0;
}