oj.uz

Submission #529672

# Submission time Handle Problem Language Result Execution time Memory
529672 2022-02-23T10:49:46 Z KoD Newspapers (CEOI21_newspapers) C++17
8 / 100
 1 ms 360 KB 
#include <bits/stdc++.h>

using std::vector;
using std::array;
using std::pair;
using std::tuple;

int main() {
    std::ios_base::sync_with_stdio(false);
    std::cin.tie(nullptr);
    int N, M;
    std::cin >> N >> M;
    if (M != N - 1) {
        std::cout << "NO\n";
        return 0;
    }
    if (N == 1) {
        std::cout << "YES\n1\n1\n";
        return 0;
    }
    vector<vector<int>> graph(N);
    for (int i = 0; i < M; ++i) {
        int a, b;
        std::cin >> a >> b;
        a -= 1, b -= 1;
        graph[a].push_back(b);
        graph[b].push_back(a);
    }
    const auto bfs = [&](const int src) {
        vector<int> dist(N, -1);
        std::queue<int> que;
        const auto push = [&](const int u, const int d) {
            if (dist[u] == -1) {
                dist[u] = d;
                que.push(u);
            }
        };
        push(src, 0);
        while (!que.empty()) {
            const int u = que.front();
            que.pop();
            for (const int v : graph[u]) {
                push(v, dist[u] + 1);
            }
        }
        return dist;
    };
    const auto dist0 = bfs(0);
    const int L = std::max_element(dist0.begin(), dist0.end()) - dist0.begin();
    const auto distL = bfs(L);
    const int R = std::max_element(distL.begin(), distL.end()) - distL.begin();
    const int D = distL[R];
    const auto distR = bfs(R);
    vector<int> path(D + 1);
    for (int i = 0; i < N; ++i) {
        if (distL[i] + distR[i] >= D + 3) {
            std::cout << "NO\n";
            return 0;
        }
        if (distL[i] + distR[i] == D) {
            path[distL[i]] = i;
        }
    }
    if (D <= 2) {
        const int cen = path[D / 2] + 1;
        std::cout << "YES\n2\n";
        std::cout << cen << ' ' << cen << '\n';
        return 0;
    }
    vector<int> ans;
    for (int i = 1; i < D; ++i) {
        const int u = path[i];
        ans.push_back(u);
        for (const int v : graph[u]) {
            if (graph[v].size() > 1 and distL[v] + distR[v] > D) {
                ans.push_back(v);
                ans.push_back(u);
            }
        }
    }
    for (int i = D - 1; i > 0; --i) {
        const int u = path[i];
        ans.push_back(u);
        for (const int v : graph[u]) {
            if (graph[v].size() > 1 and distL[v] + distR[v] > D) {
                ans.push_back(v);
                ans.push_back(u);
            }
        }
    }
    std::cout << "YES\n";
    const int n = ans.size();
    std::cout << n << '\n';
    for (int i = 0; i < n; ++i) {
        std::cout << ans[i] + 1 << " \n"[i + 1 == n];
    }
    return 0;
}

Subtask #1
0.0 / 12.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 204 KB Output is correct
2 Correct 1 ms 204 KB Output is correct
3 Correct 0 ms 204 KB Output is correct
4 Correct 0 ms 204 KB Output is correct
5 Correct 1 ms 308 KB Output is correct
6 Correct 1 ms 204 KB Output is correct
7 Correct 1 ms 204 KB Output is correct
8 Incorrect 0 ms 312 KB Output isn't correct
9 Halted 0 ms 0 KB -

Subtask #2
8.0 / 8.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 204 KB Output is correct
2 Correct 0 ms 204 KB Output is correct
3 Correct 1 ms 208 KB Output is correct
4 Correct 0 ms 204 KB Output is correct
5 Correct 1 ms 204 KB Output is correct
6 Correct 1 ms 204 KB Output is correct
7 Correct 0 ms 204 KB Output is correct
8 Correct 1 ms 204 KB Output is correct
9 Correct 1 ms 204 KB Output is correct
10 Correct 0 ms 304 KB Output is correct
11 Correct 1 ms 332 KB Output is correct
12 Correct 1 ms 360 KB Output is correct
13 Correct 1 ms 332 KB Output is correct
14 Correct 1 ms 332 KB Output is correct
15 Correct 1 ms 332 KB Output is correct
16 Correct 1 ms 332 KB Output is correct
17 Correct 1 ms 332 KB Output is correct
18 Correct 1 ms 332 KB Output is correct
19 Correct 1 ms 332 KB Output is correct
20 Correct 1 ms 332 KB Output is correct

Subtask #3
0.0 / 80.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 204 KB Output is correct
2 Correct 1 ms 204 KB Output is correct
3 Correct 0 ms 204 KB Output is correct
4 Correct 0 ms 204 KB Output is correct
5 Correct 1 ms 308 KB Output is correct
6 Correct 1 ms 204 KB Output is correct
7 Correct 1 ms 204 KB Output is correct
8 Incorrect 0 ms 312 KB Output isn't correct
9 Halted 0 ms 0 KB -