Submission #1084685

#	Time	Username	Problem	Language	Result	Execution time	Memory
1084685		SulA	Pipes (CEOI15_pipes)	C++17	20 / 100	1381 ms	65536 KiB

pipes

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

vector<int> adj[100000];
vector<bool> multi_edge[100000];
int dep[100000], low[100000];

void dfs(int v, int p, bool multi = false) {
    low[v] = dep[v] = dep[p] + 1;
    for (int j = 0; j < adj[v].size(); j++) {
        int ch = adj[v][j];
        if (ch == p) continue;
        if (dep[ch] == 0) {
            dfs(ch, v, multi_edge[v][j]);
            low[v] = min(low[v], low[ch]);
        } else {
            low[v] = min(low[v], dep[ch]);
        }
    }
    if (low[v] == dep[v] && v != p && !multi) {
        cout << v+1 << " " << p+1 << "\n";
    }
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr); cout.tie(nullptr);

    int n,m; cin >> n >> m;
    while (m--) {
        int u,v; cin >> u >> v;
        adj[--u].push_back(--v);
        adj[v].push_back(u);
    }
    for (int i = 0; i < n; i++) {
        sort(adj[i].begin(), adj[i].end());
        multi_edge[i].resize(adj[i].size());
        for (int j = 0; j < adj[i].size(); j++) {
            if (j != 0 && adj[i][j-1] == adj[i][j]) {
                multi_edge[i][j] = true;
            }
            if (j != adj[i].size()-1 && adj[i][j+1] == adj[i][j]) {
                multi_edge[i][j] = true;
            }
        }
    }
    for (int i = 0; i < n; i++) if (dep[i] == 0) dfs(i, i);
}

Compilation message (stderr)

pipes.cpp: In function 'void dfs(int, int, bool)':
pipes.cpp:10:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   10 |     for (int j = 0; j < adj[v].size(); j++) {
      |                     ~~^~~~~~~~~~~~~~~
pipes.cpp: In function 'int main()':
pipes.cpp:38:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   38 |         for (int j = 0; j < adj[i].size(); j++) {
      |                         ~~^~~~~~~~~~~~~~~
pipes.cpp:42:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   42 |             if (j != adj[i].size()-1 && adj[i][j+1] == adj[i][j]) {
      |                 ~~^~~~~~~~~~~~~~~~~~

• 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