Submission #564132

#	Time	Username	Problem	Language	Result	Execution time	Memory
564132		piOOE	Potemkin cycle (CEOI15_indcyc)	C++17	100 / 100	322 ms	172564 KiB

indcyc

#include <bits/stdc++.h>

using namespace std;

#define all(x) begin(x), end(x)
#define sz(x) ((int)size(x))
#define trace(x) cout << #x << ": " << (x) << endl;

typedef long long ll;

const int N = 1000, M = 100000;


int A[M], B[M], C[2][M];

bool e[N][N];
vector<pair<int, int>> adj[N];
vector<pair<int, int>> g[2][M];

vector<int> st;

int used[2][M];

void dfs(int t, int v, pair<int, int> p) {
    used[t][v] = 1;
    st.emplace_back(C[t][v]);
    for (auto to: g[t][v]) {
        if (to != p) {
            if (used[to.first][to.second] == 1) {
                cout << C[to.first][to.second] + 1 << " ";
                int lst = C[to.first][to.second];
                int wow = 0;
                while (true) {
                    auto u = st.back();
                    cout << u + 1 << " ";
                    if (wow && e[u][lst]) {
                        break;
                    }
                    ++wow;
                    st.pop_back();
                }
                exit(0);
            }
        }
    }
    for (auto to: g[t][v]) {
        if (to != p) {
            if (!used[to.first][to.second]) {
                dfs(to.first, to.second, {t, v});
            }
        }
    }
    used[t][v] = 2;
    st.pop_back();
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int n, r;
    cin >> n >> r;
    for (int i = 0; i < r; ++i) {
        cin >> A[i] >> B[i];
        --A[i], --B[i];
        C[0][i] = A[i];
        C[1][i] = B[i];
        adj[A[i]].emplace_back(B[i], i);
        adj[B[i]].emplace_back(A[i], i);
        e[A[i]][B[i]] = e[B[i]][A[i]] = true;
    }
    for (int v = 0; v < n; ++v) {
        for (auto [a, i]: adj[v]) {
            for (auto [b, j]: adj[v]) {
                if (i != j && !e[a][b]) {
                    int t1 = (B[i] == a);
                    int t2 = (B[j] == v);
                    g[t1][i].emplace_back(t2, j);
                }
            }
        }
    }
    for (int v = 0; v < r; ++v) {
        if (!used[0][v]) {
            dfs(0, v, {-1, -1});
        }
        if (!used[1][v]) {
            dfs(1, v, {-1, -1});
        }
    }
    cout << "no";
    return 0;
}

• Subtask 1: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 10 / 10
• Subtask 4: 10 / 10
• Subtask 5: 10 / 10
• Subtask 6: 10 / 10
• Subtask 7: 10 / 10
• Subtask 8: 10 / 10
• Subtask 9: 10 / 10
• Subtask 10: 10 / 10