Submission #874816

#	Time	Username	Problem	Language	Result	Execution time	Memory
874816		Bahamin	Pipes (CEOI15_pipes)	C++17	0 / 100	1121 ms	65536 KiB

pipes

#include <bits/stdc++.h>

using namespace std;

template<typename A, typename B> ostream& operator<<(ostream &os, const pair<A, B> &p) { return os << '(' << p.first << ", " << p.second << ')'; }
template<typename T_container, typename T = typename enable_if<!is_same<T_container, string>::value, typename T_container::value_type>::type> ostream& operator<<(ostream &os, const T_container &v) { os << '{'; string sep; for (const T &x : v) os << sep << x, sep = ", "; return os << '}'; }
void dbg_out() { cerr << endl; }
template<typename Head, typename... Tail> void dbg_out(Head H, Tail... T) { cerr << ' ' << H; dbg_out(T...); }
#ifdef LOCAL
#define dbg(...) cerr << "(" << #__VA_ARGS__ << "):", dbg_out(__VA_ARGS__)
#else
#define dbg(...)
#endif

#define ar array
#define ll long long
#define ld long double
#define sze(x) ((int)x.size())
#define all(a) (a).begin(), (a).end()
#define sui cout.tie(NULL); cin.tie(NULL); ios_base::sync_with_stdio(false)
#define mset(a, x) memset(a, x, sizeof(a))
typedef priority_queue <int, vector<int>, greater<int> > max_heap;
typedef priority_queue <int> min_heap;
const int MAX_N = 1e5 + 5;
const ll MOD = 1e9 + 7;
const ll INF = 1e9;
const ld EPS = 1e-9;

int par[2][MAX_N];
int sz[2][MAX_N];
vector<int> adj[MAX_N];

int getpar(int u, int k)
{
    return (par[k][u] == u ? u : getpar(par[k][u], k));
}

bool merge(int u, int v, int k)
{   
    u = getpar(u, k), v = getpar(v, k);
    if (u == v) return false;
    if (sz[k][u] < sz[k][v]) swap(u, v);
    par[k][v] = u;
    sz[k][u] += sz[k][v];
    return true;
}

bool mark[MAX_N];
int dp[MAX_N];
int he[MAX_N];

void dfs(int u, int h, int p)
{
    mark[u] = true;
    he[u] = h;
    dp[u] = INF;
    for (int v : adj[u])
    {
        if (!mark[v]) dfs(v, h + 1, u), dp[u] = min(dp[v], dp[u]);
        else if (he[v] < h - 1) dp[u] = min(dp[u], he[v]);
    }
    if (dp[u] >= h && p != -1) cout << u << " " << p << endl;
}

void solve() {
    int n, m;
    cin >> n >> m;
    for (int i = 1; i <= n; i++)
    {
        par[0][i] = par[1][i] = i;
        sz[0][i] = sz[1][i] = 1;
        mark[i] = false;
        dp[i] = INF;
        he[i] = INF;
        adj[i].clear();
    }
    for (int i = 0; i < m; i++)
    {
        int a, b;
        cin >> a >> b;
        bool ok = merge(a, b, 0);
        if (ok) adj[a].push_back(b), adj[b].push_back(a);
        else if (merge(a, b, 1)) adj[a].push_back(b), adj[b].push_back(a);
    }
    for (int i = 1; i <= n; i++)
    {
        if (!mark[i]) dfs(i, 0, -1);
    }
}

int main() {
    sui;
    int tc = 1;
    // cin >> tc;
    for (int t = 1; t <= tc; t++) {
        solve();
    }
}

• 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