Submission #382561

#	Time	Username	Problem	Language	Result	Execution time	Memory
382561		Mahdi_Shokoufi	Pipes (CEOI15_pipes)	C++17	90 / 100	1355 ms	22332 KiB

pipes

//In the name of Allah
#include <bits/stdc++.h>

using namespace std;

#define pb push_back

const int N = 1e5 + 10;

int par[2][N], mark[N];
vector < int > adj[N];

int getPar(int t, int v){
    return par[t][v] == v ? v : par[t][v] = getPar(t, par[t][v]);
}

bool merge(int t, int u, int v){
    u = getPar(t, u); v = getPar(t, v);
    if (u == v)
        return false;
    par[t][u] = v;
    return true;
}

void DFS(int v, int p = 0){
    mark[v] = 1;
    par[1][v] = N;
    int cnt = 0;
    for (int u : adj[v]){
        if (u == p){
            cnt ++;
            continue;
        }
        if (mark[u])
            par[1][v] = min(par[1][v], par[0][u]);
        else{
            par[0][u] = par[0][v] + 1;
            DFS(u, v);
            par[1][v] = min(par[1][v], par[1][u]);
        }
    }
    if (p && cnt == 1 && par[0][p] < par[1][v])
        cout << p << ' ' << v << '\n';
}

int main(){
    ios::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
    int n, m;
    cin >> n >> m;
    for (int i = 0; i < N; i ++)
        par[0][i] = par[1][i] = i;
    for (int i = 0; i < m; i ++){
        int u, v;
        cin >> u >> v;
        if (merge(0, u, v)){
            adj[u].pb(v);
            adj[v].pb(u);
        }
        else if (merge(1, u, v)){
            adj[u].pb(v);
            adj[v].pb(u);
        }
    }
    for (int v = 1; v <= n; v ++)
        adj[v].shrink_to_fit();
    memset(par, 0, sizeof par);
    for (int v = 1; v <= n; v ++)
        if (!mark[v])
            DFS(v);
    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: 0 / 10