제출 #134999

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
134999		lyc	Potemkin cycle (CEOI15_indcyc)	C++14	100 / 100	392 ms	91960 KiB

indcyc

#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
typedef long double ld;
typedef pair<int, int> ii;
typedef pair<int, ii> iii;
typedef pair<ii, int> ri3;
#define mp make_pair
#define pb push_back
#define fi first
#define sc second
#define SZ(x) (int)(x).size()
#define ALL(x) begin(x), end(x) 
#define REP(i, n) for (int i = 0; i < n; ++i) 
#define FOR(i, a, b) for (int i = a; i <= b; ++i)
#define RFOR(i, a, b) for (int i = a; i >= b; --i)

const int MAXN = 1e3+5;
const int MAXR = 1e5+5;
const int MAXE = 2*MAXR;

int N, R;
vector<int> al[MAXN];
bool conn[MAXN][MAXN];

vector<int> g[MAXE];
int E, from[MAXE], to[MAXE], vis[MAXE], pa[MAXE];

void bfs(int s) {
    queue<int> q;
    FOR(i,0,E-1) pa[i] = -1;
    q.push(s);
    //cout << "S " << from[s] << " " << to[s] << endl;
    while (!q.empty()) {
        int u = q.front(); q.pop();
        //cout << "U " << from[u] << " " << to[u] << endl;
        for (int v : g[u]) {
            //cout << "\t\tV " << from[v] << " " << to[v] << endl;
            if (v == s) {
                //cout << "ANS" << '\n';
                //vector<int> edges;
                //for (int e = u; e != -1; e = pa[e]) edges.push_back(e);
                //for (auto& e : edges) { cout << from[e] << " " << to[e] << " :: "; } cout << endl;
                for (int e = u; e != -1; e = pa[e]) cout << to[e] << (pa[e]==-1?'\n':' ');
                exit(0);
            } else if (pa[v] == -1) pa[v] = u, q.push(v);
        }
    }
}

void dfs(int u) {
    vis[u] = 2;
    for (int v : g[u]) {
        if (vis[v] == 2) {
            bfs(v); // ans
        } else if (!vis[v]) dfs(v);
    }
    vis[u] = 1;
}

int main() {
    //freopen("in.txt", "r", stdin);
    ios::sync_with_stdio(false);
    cin.tie(0);

    cin >> N >> R; E = 0;
    FOR(i,1,R){
        int A, B; cin >> A >> B;
        from[E] = A, to[E] = B;
        al[A].push_back(E++);
        from[E] = B, to[E] = A;
        al[B].push_back(E++);
        conn[A][B] = conn[B][A] = 1;
    }

    FOR(i,1,N) FOR(j,0,SZ(al[i])-1) { // + ^ O(E)
        FOR(k,j+1,SZ(al[i])-1) { // O(N)
            int e = al[i][j], f = al[i][k];
            if (!conn[to[e]][to[f]]) g[e^1].push_back(f), g[f^1].push_back(e);
        }
    }

    FOR(i,0,E-1) vis[i] = 0;
    FOR(i,0,E-1) if (!vis[i]) dfs(i);
    cout << "no" << '\n';
}

• 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