Submission #550072

#	Time	Username	Problem	Language	Result	Execution time	Memory
550072		SmolBrain	Pipes (CEOI15_pipes)	C++17	20 / 100	370 ms	43740 KiB

pipes

// Om Namah Shivaya
// GM in 107 days

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

typedef long long int ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

#define fastio ios_base::sync_with_stdio(false); cin.tie(NULL)
#define endl '\n'
#define pb push_back
#define conts continue

#define rep(i,n) for(int i = 0; i < n; ++i)
#define rep1(i,n) for(int i = 1; i <= n; ++i)
#define rev(i,s,e) for(int i = s; i >= e; --i)
#define trav(i,a) for(auto &i : a)

template<typename T> void amin(T &a, T b) { a = min(a, b); }
template<typename T> void amax(T &a, T b) { a = max(a, b); }

const int maxn = 3e4 + 1;
const int inf1 = 1e9 + 5;

vector<pii> adj[maxn];
vector<int> tin(maxn), low(maxn, inf1);
bitset<maxn> vis;
int timer = 1;

void dfs(int node, int prevedge) {
    vis[node] = 1;
    tin[node] = timer++;

    for (auto [child, id] : adj[node]) {
        if (vis[child]) {
            if (id != prevedge) {
                // back edge
                amin(low[node], tin[child]);
            }
        }
        else {
            // front edge
            dfs(child, id);
            amin(low[node], low[child]);

            if (low[child] > tin[node]) {
                cout << node << " " << child << endl;
            }
        }
    }
}

void solve(int test_case)
{
    int n, m; cin >> n >> m;
    rep1(i, m) {
        int u, v; cin >> u >> v;
        adj[u].pb({v, i}), adj[v].pb({u, i});
    }

    rep1(i, n) {
        if (vis[i]) conts;
        dfs(i, -1);
    }
}

int main()
{
    fastio;

    int t = 1;
    // cin >> t;
    rep1(i, t) {
        solve(i);
    }

    return 0;
}

• Subtask 1: 10 / 10
• Subtask 2: 10 / 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