Submission #1043346

#	Time	Username	Problem	Language	Result	Execution time	Memory
1043346		Pekiban	Pipes (CEOI15_pipes)	C++17	40 / 100	659 ms	65536 KiB

pipes

#include <bits/stdc++.h>

using namespace std;
#define pb push_back

const int N = 1e5+5;
mt19937 rng(time(0));
// upravo sam imao najgenijalniju ideju svih vremena
vector<int> g[N];
int p[N];
long long dp[N];
int get(int x) {
    if (x == p[x])  return x;
    return p[x] = get(p[x]);
}
bool unite(int u, int v) {
    if (get(u) == get(v))   return 0;
    p[get(v)] = get(u);
    g[u].pb(v); g[v].pb(u);
    return 1;
}
void upd(int u, int v) {
    long long x = rng() % (1LL << 62);
    dp[u] ^= x;
    dp[v] ^= x;
}
vector<array<int, 2>> ans;
void dfs(int s, int e = 0) {
    for (auto u : g[s]) {
        if (u == e) continue;
        dfs(u, s);
        dp[s] ^= dp[u];
    }
    if (e && !dp[s])    ans.pb({e, s});
}
bitset<N> vis;
int main() {
    ios::sync_with_stdio(0);
    cin.tie(0);
    iota(p, p+N, 0);
    int n, m;
    cin >> n >> m;
    int u, v;
    for (int i = 0; i < m; ++i) {
        cin >> u >> v;
        if (!unite(u, v))   upd(u, v);
    }
    for (int i = 1; i <= n; ++i) {
        if (!vis[get(i)]) {
            dfs(get(i));
            vis[get(i)] = 1;
        }
    }
    // for (int i = 1; i <= n; ++i) {
    //     cout << i << ':';
    //     for (auto x : g[i]) {
    //         cout << x << ' ';
    //     }
    //     cout << '\n';
    // }
    for (auto &[x, y] : ans) {
        if (x > y)  swap(x, y);
    }
    sort(ans.begin(), ans.end());
    for (auto [x, y] : ans) {
        cout << x << ' ' << y << '\n';
    }
}

• Subtask 1: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 10 / 10
• Subtask 4: 10 / 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