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Submission #1004748

# Submission time Handle Problem Language Result Execution time Memory
1004748 2024-06-21T13:35:55 Z Valaki2 Potemkin cycle (CEOI15_indcyc) C++14
30 / 100
 90 ms 2140 KB 
#include <bits/stdc++.h>
using namespace std;

#define pb push_back

const int maxn = 1000;

int n, m;
vector<int> graph[1 + maxn];
bool matrix[1 + maxn][1 + maxn];
bool neigh[1 + maxn];
int cur_mid;
int dist[1 + maxn];
int prv[1 + maxn];
int goal;

void bfs(int start) {
    queue<int> q;
    queue<int> all;
    q.push(start);
    all.push(start);
    prv[start] = -1;
    while(!q.empty()) {
        int cur = q.front();
        q.pop();
        for(int nei : graph[cur]) {
            if(prv[nei] == 0 && (!neigh[cur] || (cur == start && !neigh[nei]))) {
                q.push(nei);
                all.push(nei);
                dist[nei] = dist[cur] + 1;
                prv[nei] = cur;
                if(nei == goal) {
                    while(nei != start) {
                        cout << nei << " ";
                        nei = prv[nei];
                    }
                    cout << start << " " << cur_mid << "\n";
                    exit(0);
                }
            }
        }
    }
    while(!all.empty()) {
        dist[all.front()] = prv[all.front()] = 0;
        all.pop();
    }
}

bool vis[1 + maxn];
vector<int> this_comp;

bool been[1 + maxn];

void do_bfs(int start) {
    queue<int> q;
    q.push(start);
    vis[start] = true;
    been[start] = true;
    while(!q.empty()) {
        int cur = q.front();
        q.pop();
        if(neigh[cur]) {
            this_comp.pb(cur);
        }
        for(int nei : graph[cur]) {
            if(!vis[nei]) {
                q.push(nei);
                vis[nei] = true;
                been[nei] = true;
            }
        }
    }
}

void try_for(int cur) {
    cur_mid = cur;
    if(graph[cur].empty()) {
        return;
    }
    for(int nei : graph[cur]) {
        neigh[nei] = true;
    }
    neigh[cur] = true;
    for(int i = 1; i <= n; i++) {
        if(!neigh[i] && !been[i]) {
            do_bfs(i);
            int m = (int) this_comp.size();
            for(int j = 0; j < m; j++) {
                for(int k = j + 1; k < m; k++) {
                    if(!matrix[this_comp[j]][this_comp[k]]) {
                        goal = this_comp[k];
                        bfs(this_comp[j]);
                    }
                }
            }
            for(int x : this_comp) {
                been[x] = vis[x] = false;
            }
        }
    }
    for(int nei : graph[cur]) {
        neigh[nei] = false;
    }
    neigh[cur] = false;
    for(int i = 1; i <= n; i++) {
        vis[i] = false;
        been[i] = false;
    }
}

void solve() {
    cin >> n >> m;
    for(int i = 1; i <= m; i++) {
        int a, b;
        cin >> a >> b;
        graph[a].pb(b);
        graph[b].pb(a);
        matrix[a][b] = matrix[b][a] = true;
    }
    for(int i = 1; i <= n; i++) {
        try_for(i);
    }
    cout << "no\n";
}

signed main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    solve();
}

Subtask #1
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 0 ms 348 KB Output is correct

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct

Subtask #3
0 / 10.0

# Verdict Execution time Memory Grader output
1 Incorrect 0 ms 344 KB Wrong adjacency
2 Halted 0 ms 0 KB -

Subtask #4
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct

Subtask #5
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 856 KB Output is correct
2 Incorrect 0 ms 600 KB Wrong answer on graph without induced cycle
3 Halted 0 ms 0 KB -

Subtask #6
0 / 10.0

# Verdict Execution time Memory Grader output
1 Incorrect 1 ms 604 KB Wrong answer on graph without induced cycle
2 Halted 0 ms 0 KB -

Subtask #7
0 / 10.0

# Verdict Execution time Memory Grader output
1 Incorrect 1 ms 604 KB Wrong adjacency
2 Halted 0 ms 0 KB -

Subtask #8
0 / 10.0

# Verdict Execution time Memory Grader output
1 Incorrect 90 ms 2004 KB Wrong adjacency
2 Halted 0 ms 0 KB -

Subtask #9
0 / 10.0

# Verdict Execution time Memory Grader output
1 Incorrect 3 ms 1624 KB Wrong adjacency
2 Halted 0 ms 0 KB -

Subtask #10
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 10 ms 1880 KB Output is correct
2 Correct 9 ms 1884 KB Output is correct
3 Incorrect 10 ms 2140 KB Wrong adjacency
4 Halted 0 ms 0 KB -