Submission #660405

#	Time	Username	Problem	Language	Result	Execution time	Memory
660405		Dec0Dedd	Information (CEOI08_information)	C++14	100 / 100	456 ms	25476 KiB

information

#include <bits/stdc++.h>

using namespace std;

#define pii pair<short, int>

const int N = 2e3+1;
const int M = 1e6+1;

int c[M], n, m, tin[N], tout[N], t=1;
bool vis[N];
vector<pii> G[N], up[N];
pii e[M];

bool anc(int v, int u) {
    return tin[v] <= tin[u] && tout[u] <= tout[v];
}

void dfs(int v) {
    vis[v]=true; tin[v]=t++;
    for (auto u : G[v]) {
        if (vis[u.first]) continue;
        c[u.second]=1, dfs(u.first);
    }
    tout[v]=t++;
}

void dfs2(int v) {
    vis[v]=true;
    for (auto u : G[v]) {
        if (vis[u.first]) continue;
        if (c[u.second] == 0) {
            c[u.second]=2; dfs2(u.first);
        } else {
            while (up[u.first].size() > 0) {
                pii x=up[u.first].back();
                if (c[x.second] != 0) up[u.first].pop_back();
                else break;
            }
            if (!up[u.first].empty()) {
                c[u.second]=2, c[up[u.first].back().second]=1;
                up[u.first].pop_back();
                dfs2(u.first);
            }
        }
    }
}

int main() {
    cin>>n>>m;
    for (int i=1; i<=m; ++i) {
        int a, b; cin>>a>>b;
        e[i]={a, b};
        G[a].push_back({b, i});
    } dfs(1);

    memset(vis, false, sizeof(vis));

    for (int i=1; i<=n; ++i) {
        for (auto u : G[i]) {
            if (c[u.second] == 0 && anc(i, u.first)) up[u.first].push_back({i, u.second});
        }
    }

    dfs2(1);

    vector<int> l, r;
    for (int i=1; i<=m; ++i) {
        if (c[i] == 1) l.push_back(i);
        else if (c[i] == 2) r.push_back(i);
    }

    if ((int)l.size() < n-1 || (int)r.size() < n-1) cout<<"NONE\n";
    else {
        for (auto u : l) cout<<u<<" ";
        cout<<"\n";
        for (auto u : r) cout<<u<<" ";
        cout<<"\n";
    }
}

• Subtask 1: 4 / 4
• Subtask 2: 4 / 4
• Subtask 3: 4 / 4
• Subtask 4: 4 / 4
• Subtask 5: 4 / 4
• Subtask 6: 4 / 4
• Subtask 7: 4 / 4
• Subtask 8: 4 / 4
• Subtask 9: 4 / 4
• Subtask 10: 4 / 4
• Subtask 11: 4 / 4
• Subtask 12: 4 / 4
• Subtask 13: 4 / 4
• Subtask 14: 4 / 4
• Subtask 15: 4 / 4
• Subtask 16: 4 / 4
• Subtask 17: 4 / 4
• Subtask 18: 4 / 4
• Subtask 19: 4 / 4
• Subtask 20: 4 / 4
• Subtask 21: 5 / 5
• Subtask 22: 5 / 5
• Subtask 23: 5 / 5
• Subtask 24: 5 / 5