Submission #527270

#	Time	Username	Problem	Language	Result	Execution time	Memory
527270		beepbeepsheep	Pipes (CEOI15_pipes)	C++17	0 / 100	2053 ms	65540 KiB

pipes

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

#define ll int
#define ii pair<ll,ll>
#define endl '\n'
const ll mod=1e9+7;
const ll maxn=1e5+5;


set<ii> s;
vector<ll> adj[maxn];
ll vis[maxn][2];
ll cnt;
void dfs(ll a, ll p){
    vis[a][0]=vis[a][1]=cnt++;
    for (auto &u:adj[a]){
        if (vis[u][1]!=-1){
            if (u!=p){
                vis[a][0]=min(vis[u][1],vis[a][0]);
            }
            continue;
        }
        dfs(u,a);
        if (vis[u][0]>vis[a][1] && s.find(make_pair(u,a))==s.end()){
            cout<<a<<' '<<u<<endl;
        }
        vis[a][0]=min(vis[u][0],vis[a][0]);
    }
}
int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    ll n,e,a,b;
    cin>>n>>e;
    for (int i=0;i<e;i++){
        cin>>a>>b;
        adj[a].emplace_back(b);
        adj[b].emplace_back(a);
    }
    for (int i=1;i<=n;i++){
        sort(adj[i].begin(),adj[i].end());
        for (int j=0;j<max<int>(0,adj[i].size()-1);j++){
            if (adj[i][j]==adj[i][j+1]){
                s.emplace(i,adj[i][j]);
            }
        }
    } 
    for (int i=1;i<=n;i++){
        if (vis[i][1]!=-1) continue;
        cnt=0;
        dfs(i,-1);
    }
    return 0;
}

• Subtask 1: 0 / 10
• Subtask 2: 0 / 10
• Subtask 3: 0 / 10
• Subtask 4: 0 / 10
• Subtask 5: 0 / 10
• Subtask 6: 0 / 10
• Subtask 7: 0 / 10
• Subtask 8: 0 / 10
• Subtask 9: 0 / 10
• Subtask 10: 0 / 10