Submission #328733

#	Time	Username	Problem	Language	Result	Execution time	Memory
328733		dolphingarlic	Pipes (CEOI15_pipes)	C++14	40 / 100	1286 ms	65536 KiB

pipes

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

int cmp1[100001], cmp2[100001];
vector<int> graph[100001];
bool visited[100001];
int tin[100001], low[100001], timer = 0;

int find(int A, int *cmp) {
    while (cmp[A] != A) cmp[A] = cmp[cmp[A]], A = cmp[A];
    return A;
}

void onion(int A, int B, int *cmp) {
    cmp[find(A, cmp)] = find(B, cmp);
}

void dfs(int node, int parent = 0) {
    visited[node] = true;
    tin[node] = low[node] = timer++;
    sort(graph[node].begin(), graph[node].end());
    for (int ptr = 0; ptr < graph[node].size(); ptr++) {
        int i = graph[node][ptr];
        if (i != parent) {
            if (visited[i]) low[node] = min(low[node], tin[i]);
            else {
                dfs(i, node);
                low[node] = min(low[node], low[i]);
                if (low[i] > tin[node] && (i + 1 == graph[node].size() || i != graph[node][ptr + 1]) && (!i || i != graph[node][ptr - 1])) cout << node << ' ' << i << '\n';
            }
        }
    }
}

int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    int n, m;
    cin >> n >> m;
    iota(cmp1 + 1, cmp1 + n + 1, 1);
    iota(cmp2 + 1, cmp2 + n + 1, 1);
    while (m--) {
        int u, v;
        cin >> u >> v;
        if (find(u, cmp1) != find(v, cmp1)) {
            onion(u, v, cmp1);
            graph[u].push_back(v);
            graph[v].push_back(u);
        } else if (find(u, cmp2) != find(v, cmp2)) {
            onion(u, v, cmp2);
            graph[u].push_back(v);
            graph[v].push_back(u);
        }
    }
    for (int i = 1; i <= n; i++) if (!visited[i]) dfs(i);
    return 0;
}

Compilation message (stderr)

pipes.cpp: In function 'void dfs(int, int)':
pipes.cpp:23:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   23 |     for (int ptr = 0; ptr < graph[node].size(); ptr++) {
      |                       ~~~~^~~~~~~~~~~~~~~~~~~~
pipes.cpp:30:50: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   30 |                 if (low[i] > tin[node] && (i + 1 == graph[node].size() || i != graph[node][ptr + 1]) && (!i || i != graph[node][ptr - 1])) cout << node << ' ' << i << '\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