Submission #1116808

#	Time	Username	Problem	Language	Result	Execution time	Memory
1116808		byebye75	Mergers (JOI19_mergers)	C++14	0 / 100	16 ms	2896 KiB

mergers

#include <iostream>
#include <vector>
#include <unordered_set>
#include <cstdint>

using namespace std;

// Custom hash function for pairs (if needed)
struct pair_hash {
    size_t operator()(const pair<int, int>& p) const {
        // Combine the hashes of the two integers
        return hash<int>()(p.first) ^ (hash<int>()(p.second) << 1);
    }
};

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    int N, K;
    cin >> N >> K;

    vector<pair<int, int>> edges(N - 1);
    for (int i = 0; i < N - 1; ++i) {
        int Ai, Bi;
        cin >> Ai >> Bi;
        --Ai; // Convert to 0-based index
        --Bi;
        edges[i] = {Ai, Bi};
    }

    vector<int> S(N);
    for (int i = 0; i < N; ++i) {
        cin >> S[i];
        --S[i]; // Convert to 0-based index
    }

    unordered_set<int64_t> state_edges;

    for (const auto& edge : edges) {
        int u = edge.first;
        int v = edge.second;
        int su = S[u];
        int sv = S[v];
        if (su != sv) {
            int s = min(su, sv);
            int t = max(su, sv);
            int64_t key = (int64_t)s * 500000 + t;
            state_edges.insert(key);
        }
    }

    int E = state_edges.size(); // Number of edges in the state graph
    int N_states = K; // Number of nodes in the state graph

    int cycles_initial = E - N_states + 1;

    int answer = max(0, 1 - cycles_initial);

    cout << answer << '\n';

    return 0;
}

• Subtask 1: 0 / 10
• Subtask 2: 0 / 24
• Subtask 3: 0 / 14
• Subtask 4: 0 / 22
• Subtask 5: 0 / 30