Submission #527330

#	Time	Username	Problem	Language	Result	Execution time	Memory
527330		joelau	Pipes (CEOI15_pipes)	C++14	60 / 100	1032 ms	26272 KiB

pipes

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

int N,M, ufds[100005], rnk[100005], ufds1[100005], rnk1[100005], low[100005], depth[100005], p[100005];
vector< pair<int,int> > lst[100005];
bitset<100005> visited;

int findSet(int i) {
    return ufds[i] == i ? i : ufds[i] = findSet(ufds[i]);
}

void unionSet (int i, int j) {
    int a = findSet(i), b = findSet(j);
    if (a == b) return;
    if (rnk[a] < rnk[b]) ufds[a] = b;
    if (rnk[a] > rnk[b]) ufds[b] = a;
    if (rnk[a] == rnk[b]) ufds[a] = b, rnk[b]++;
}

int findSet1(int i) {
    return ufds1[i] == i ? i : ufds1[i] = findSet1(ufds1[i]);
}

void unionSet1 (int i, int j) {
    int a = findSet1(i), b = findSet1(j);
    if (a == b) return;
    if (rnk1[a] < rnk1[b]) ufds1[a] = b;
    if (rnk1[a] > rnk1[b]) ufds1[b] = a;
    if (rnk1[a] == rnk1[b]) ufds1[a] = b, rnk1[b]++;
}

void dfs (int u, int d) {
    visited[u] = 1, depth[u] = d, low[u] = d;
    for (auto v: lst[u]) {
        if (!visited[v.first]) {
            p[v.first] = v.second;
            dfs(v.first,d+1);
            if (low[v.first] > depth[u]) cout << u+1 << ' ' << v.first+1 << '\n';
            low[u] = min(low[u],low[v.first]);
        }
        else if (v.second != p[u])
            low[u] = min(low[u],depth[v.first]);
    }
}

int main() {
    ios_base::sync_with_stdio(false); cin.tie(NULL);
    cin >> N >> M;
    for (int i = 0; i < N; ++i) ufds[i] = i, rnk[i] = 1, ufds1[i] = i, rnk1[i] = 1;
    for (int i = 0; i < M; ++i) {
        int u,v; cin >> u >> v; u--, v--;
        if (findSet(u) != findSet(v)) {
            unionSet(u,v);
            lst[u].emplace_back(v,i), lst[v].emplace_back(u,i);
        }
        else if (findSet1(u) != findSet1(v)) {
            unionSet1(u,v);
            lst[u].emplace_back(v,i), lst[v].emplace_back(u,i);
        }
    }
    for (int i = 0; i < N; ++i) if (!visited[i]) dfs(i,0);

    return 0;
}

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