Submission #986227

#	Time	Username	Problem	Language	Result	Execution time	Memory
986227		dorjderem	The Xana coup (BOI21_xanadu)	C++17	0 / 100	518 ms	524288 KiB

xanadu

#include <iostream>
#include <vector>
#include <queue>
#include <cstdlib> // For std::exit()

using namespace std;

#define ull unsigned long long

int main()
{
    int n;
    cin >> n;

    vector<vector<int>> adj(n);
    int a, b;
    for (int i = 0; i < n - 1; ++i)
    {
        cin >> a >> b;
        --a;
        --b;
        adj[a].push_back(b);
        adj[b].push_back(a);
    }

    ull state = 0;
    for (int i = 0; i < n; ++i)
    {
        int temp;
        cin >> temp;
        if (temp == 1)
        {
            state |= (1ULL << i);
        }
    }

    for (int i = 0; i < n; i++)
    {
        queue<pair<int, ull>> q;
        q.push(make_pair(i, state));

        int level = 0;
        while (!q.empty() && level < 15)
        {
            int q_size = q.size();
            for (int j = 0; j < q_size; ++j)
            {
                auto front = q.front();
                q.pop();

                int node = front.first;
                ull current_state = front.second;

                if (current_state == 0)
                {
                    cout << level << endl;
                    return 0;
                }
                current_state ^= (1ULL << node);
                for (int neighbor : adj[node])
                {
                    current_state ^= (1ULL << neighbor);
                }
                for (int k = 0; k < n; ++k)
                {
                    if (k != node)
                    {
                        q.push(make_pair(k, current_state));
                    }
                }
            }
            ++level;
        }
    }

    cout << "IMPOSSIBLE" << endl;

    return 0;
}

• Subtask 1: 0 / 5
• Subtask 2: 0 / 15
• Subtask 3: 0 / 10
• Subtask 4: 0 / 40
• Subtask 5: 0 / 30